Download Master thesis - Cairo University Scholars

Management of Temporal Bone Malignancy
Essay Submitted for Partial Fulfillment of Master Degree in
Otorhinolaryngology
By
Ahmed Fathy Mohamed Eldehn
(M.B.B.Ch, Faculty of Medicine - Cairo University)
Under the supervision of
Prof. Ismail Zohdi
Professor of Otorhinolaryngology
Faculty of Medicine
Cairo University
Prof. Louay El Sharkawy
Professor of Otorhinolaryngology
Faculty of Medicine
Cairo University
Dr. Baher Ashour
Lecturer of Otorhinolaryngology
Faculty of Medicine
Cairo University
2010
ACKNOWLEDGEMENTS
Above all, I would like to thank GOD who made all things possible. He is
always there for me throughout my life. Without him, I could not have completed
this work.
I would like to acknowledge and extend my heartfelt gratitude to the
following persons who have made the completion of this work possible.
This work would not have been possible without the help, support and
patience of my principal supervisor, Prof. Ismail Zohdi, Professor of
Otolaryngology, Faculty of Medicine, Cairo University, not to mention his advice,
vital encouragement and support.
The good advice, support and friendship of my second supervisor, Prof.
Louay El Sharkawy, Professor of Otolaryngology, Faculty of Medicine, Cairo
University, has been invaluable on both an academic and a personal level, for
which I am extremely grateful.
Many thanks for my third supervisor, Dr. Baher Ashour, Lecturer of
Otolaryngology, Faculty of Medicine, Cairo University, for his understanding,
assistance and expert guidance.
Also my parents that have given me their obvious support and love
throughout my life for which my mere expression of thanks does not suffice.
I also thank all the professors in the Otolaryngology Department, Faculty of
Medicine, Cairo University, for their support and assistance since the start of my
residency in 2006.
Last, but by no means least, I would like to thank my colleagues and my
friends for their kindness, friendship, encouragement and support.
My apologies if I have accidentally omitted anyone to whom
acknowledgement is due.
Thank you
Contents
Anatomy of the Temporal Bone
1
Pathology of Temporal Bone Malignancy
22
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Squamous cell and basal cell carcinoma
Malignant Melanoma
Merkel-cell carcinoma
Adenexal carcinoma of the ear
Sarcomas of the ear
Endolymphatic sac tumor
Multiple myeloma, and plasmacytoma of the middle and inner ear
Lymphoma of the temporal bone
Metastatic carcinoma of temporal bone
Patterns of Spread
Staging Systems
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Clinical Assessment of Temporal Bone Malignancy
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Radiological Diagnosis of Temporal Bone Malignancy
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Computed Tomography of the temporal bone
Magnetic resonance imaging of the temporal bone
Registration and Fusion of CT and MRI Of the Temporal Bone
Surgical Management of Temporal Bone Malignancy
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Lateral temporal bone resections
Subtotal Temporal bone resection
Total Temporal Bone Resection
Reconstruction after temporal bone surgery
Complications of temporal bone resection
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Radiotherapy and Stereotactic Radiosurgery in Temporal Bone
Malignancy
86
Prognosis & Outcome of Temporal Bone Malignancy
102
Report of a case
107
Summary
113
References
116
I
List of Abbreviations
EAC
TMJ
IAC
V
VIII
IX
X
XI
XII
CEV
IPS
AIDS
ICA
CT
PACS
3D
MRI
CSF
PT
MT
PosT
SE
192
Ir
Gy
MeV
MV
LINAC
APS
EBRT
LTBR
STBR
TTBR
External Auditory Canal
Temporo-Mandibular Joint
Internal auditory canal
Trigeminal
Vestibulo-Cochlear
Glossopharyngeal
Vagus
Accessory
Hypoglossal
Condylar emissary vein
inferior petrosal sinus
Acquired Immune Deficiency Syndrome
Internal carotid artery
Computed Tomography
picture archiving and communications systems
3 Dimension
Magnetic Resonance Imaging
Cerebrospinal fluid
Protympanum
Mesotympanum
Posterior tympanum
Spin Echo
Iriduim
Grey
Mega electron volt
Mega volt
linear accelerator
automated positioning system
External beam radiation therapy
Lateral temporal bone resection
Subtotal temporal bone resection
Total temporal bone resection
II
List of Figures
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of figure
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Title
Page
Lateral view, left temporal bone.
Medial view, left temporal bone.
Superior view, left temporal bone.
Inferior view,
The tympanic membrane
Schematic view of the middle ear cleft.
Internal auditory canal.
The view of cranial nerves IX, X, and XI after removal of the
medial wall of the jugular bulb
Intracranial view of the posterior surface of the petrous bone
showing cranial nerves V, VIII, IX, X, XI, and XII.
Merkel-cell carcinoma of the antitragus in a 72-year-old man.
Glandular tumors (microscopic picture)
Embryonal rhabdomyosarcoma
Chondrosarcoma
Kaposi’s sarcoma of a 23-year-old man with AIDS
Histopathologic examination of endolymphatic sac tumor
Plasma cell tumor
Coronal anatomy of pathways of spread of primary cancer of the
external auditory canal.
Photograph of the left ear shows a tumor extruding from the
External auditory canal
Sensation 64 scanner equipped with 32 detectors and two sources
Axial CT image at the level of the left temporomandibular joint
demonstrating the S-shape and the junction of the cartilaginous
and bony portions of the external auditory canal
Coronal CT image at the mid bony portion of the left external
auditory canal.
Axial CT images of the right middle and inner ear from caudal to
cephalic
Axial CT images of the right middle and inner ear from caudal to
cephalic
Axial CT images of the right middle and inner ear from caudal to
cephalic
Oblique coronal CT scan shows an extensive destructive lesion
of the left temporal bone with mottled calcification
An endolymphatic sac tumor. CT scan reveals the tumor
extensions
An MRI scanner.
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Magnetic resonance imaging of the internal acoustic canal
Rhabdomyosarcoma
Adenoid cystic carcinoma
Registration and Fusion of CT and MRI Of the Temporal Bone
Types of temporal bone resections
lateral temporal bone resection type I
lateral temporal bone resection type II
lateral temporal bone resection type III
lateral temporal bone resection type IV
A: Incisions vary according to whether the tumor is contained in
the temporal bone. B: The facial nerve can be divided
peripherally at the distal branches or centrally at the facial nerve
trunk, depending on involvement of the parotid gland. C: After
osteotomies and removal of the zygomatic arch and mandibular
segments, dissection in the infratemporal fossa continues
(A) Incision marked out for extended temporal bone excision.
(B) First step is to place colored slings around the great vessels
in order to ensure vascular control and identify cranial nerves IX,
X, XI, and XII prior to completing the supra-omohyoid neck
dissection. (C) Wide access and good visualization of the jugular
and carotid foramina and skull base is essential before
completing the en bloc extended temporal bone excision. (D)
View of the large defect on completion of the resection
Example of treatment portal for tumor of the middle ear
involving the petrous bone.
Radiation technique for treatment of T3N1 carcinoma of the
external auditory canal
Dose distribution for brachytherapy treatment of EAC
recurrence.
Stereotactic radiosurgery technique
John Adler and the Cyberknife
Lateral extent of the mass in the case report
Operative view showing markings before the incision
Intraoperative view showing the incision.
Intraoperative view showing anterior and posterior flap
elevations.
Intraoperative view after neck dissection and temporal
craniotomy.
Intraoperative view after resection
The specimen (lateral aspect).
Immediate postoperative view.
IV
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Anatomy
of
The Temporal Bone
Anatomy of The Temporal Bone
The temporal bone is a composite structure consisting of the tympanic
bone, mastoid process, squama (also known as the squamous portion of the
temporal bone), and petrosa (also known as the petrous portion of the
temporal bone). Although the styloid process is closely related to the
temporal bone, it is not considered a portion of it (Gulya and Schuknecht,
2007).
External Auditory Canal (EAC)
EAC is a part of the external ear transmitting sounds from the auricle
to the tympanic membrane; the lateral one-third of the EAC comprises a
continuation of the cartilage of the pinna and is deficient superiorly at the
incisura terminalis. The two or three variably present perforations in the
anterior aspect of the cartilaginous canal are the fissures of Santorini. The
remaining medial two-thirds of the approximately 2.5-cm length of the canal
are bony. The isthmus is the narrowest portion of the EAC. It lies just medial
to the junction of the bony and cartilaginous canals. The skin of the
cartilaginous canal has a substantial subcutaneous layer contains hair
follicles, sebaceous glands, and cerumen glands. The skin of the osseous
canal is very thin and its subcutaneous layer is devoid of the usual adnexal
structures. Accordingly, the absence of hair serves to distinguish the bony
and cartilaginous canals (Saleh et al., 1995).
The pinna and EAC are supplied by a variety of sensory nerves. The
auriculotemporal branch of the trigeminal nerve, greater auricular nerve (a
branch of C3), lesser occipital nerve (of C2 and C3 derivation), auricular
branch of the vagus nerve (Arnold’s nerve), and twigs from the facial nerve
Management of Temporal Bone Malignancy
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Anatomy of The Temporal Bone
all contribute to the sensory innervation of the pinna and EAC (Eshraghi et
al., 2001).
The tympanic, squamous, and mastoid portions of the temporal bone
are evident on the lateral view.
Figure 1: Lateral view, left temporal bone. The temporal line, extending posteriorly from
the root of the zygoma, approximates the inferior descent of the dura medially as well as
the inferior attachment of the temporalis muscle laterally.
1- squama, 2- temporal line, 3 -mastoid fossa, 4- Henle’s spine,
5- tympanosquamosal suture, 6- mastoid foramen, 7- mastoid process,
8- external auditory canal, 9- zygoma, 10- petrotympanic fissure, 11- tympanic bone,
12- mandibular fossa, 13 – styloid process. (Gulya and Schuknecht, 2007).
The tympanic bone forms the anterior, inferior, and parts of the
posterior wall of the EAC. It interfaces with the squama at the
tympanosquamous suture, the mastoid at the tympanomastoid suture, and the
petrosa at the petrotympanic fissure and constitutes the posterior wall of the
Management of Temporal Bone Malignancy
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Anatomy of The Temporal Bone
glenoid fossa for the temporo mandibular joint (TMJ). The tympanomastoid
suture is traversed by Arnold’s nerve, while the chorda tympani nerve and
anterior tympanic artery traverse the petrotympanic fissure. Henle’s spine is
a projection of variable prominence at the posterosuperior aspect of the
EAC. Inferiorly, the vaginal process, a projection of the tympanic bone,
forms the sheath of the styloid bone. Laterally, the tympanic bone borders
the cartilaginous EAC, whereas medially it bears a circular groove, the
annular sulcus. The annular sulcus houses the annulus of the tympanic
membrane except superiorly, where it is deficient; at this point, known as the
notch of Rivinus, the tympanic membrane attaches directly to the squama
(Hughes and Pensak, 1997).
The squamous portion of the temporal bone serves as the lateral wall
of the middle cranial fossa and interfaces with the parietal bone superiorly
and with the zygomatic process and the sphenoid anteriorly. Its medial
surface is grooved by a sulcus for the middle meningeal artery, whereas the
middle temporal artery runs in a groove on its lateral aspect (Hughes and
Pensak, 1997).
Management of Temporal Bone Malignancy
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Anatomy of The Temporal Bone
Figure 2: Medial view, left temporal bone. The meeting of the posterior and middle fossa
faces of the temporal bone occurs at the sulcus for the superior petrosal sinus.
1 – Superior petrosal sulcus, 2 – arcuate eminence, 3 – squama, 4 – sigmoid sulcus,
5 – petromastoid canal, 6 – middle meningeal artery sulcus, 7 – internal auditory canal,
8 – petrous apex, 9 – styloid process, 10 – internal carotid artery foramen. (Gulya and
Schuknecht, 2007).
The mastoid portion of the temporal bone is the inferiorly extending
projection seen on the lateral surface of the temporal bone. It is composed of
a squamous portion (laterally) and a petrous portion (medially) separated by
Korner’s (petrosquamous) septum. The fossa mastoidea (MacEwen’s
triangle) is defined by the linea temporalis (temporal line), a ridge of bone
extending posteriorly from the zygomatic process (marking the lower margin
of the temporalis muscle and approximating the inferior descent of the
middle cranial fossa dura), the posterosuperior margin of the EAC, and a
tangent to the posterior margin of the EAC. The fossa mastoidea, a cribrose
(cribriform) area, is identified by its numerous, perforating small blood
Management of Temporal Bone Malignancy
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Anatomy of The Temporal Bone
vessels. The mastoid foramen, located posteriorly on the mastoid process, is
traversed by the mastoid emissary vein and one or two mastoid arteries.
Inferiorly, the sternocleidomastoid muscle attaches to the mastoid tip. The
fossa mastoidea is an important surgical landmark as it laterally overlies the
mastoid antrum. The mastoid antrum, medial to the fossa mastoidea
(Macewen’s triangle), develops in the earliest stages of mastoid
pneumatization and is ordinarily present in even the least pneumatized
temporal bones (Gulya and Schuknecht, 2007).
The petrosa; the term “petrous” (Greek for “rocklike”) stems from the
extreme density of its bone, which guards the sensory organs of the inner
ear. Important landmarks seen on a superior view are the arcuate eminence
(roughly corresponding to the superior semicircular canal), meatal plane
(indicative of the internal auditory canal), foramen spinosum for the middle
meningeal artery, and facial hiatus (marking the departure of the greater
petrosal nerve from the anterior aspect of the geniculate ganglion). The
lesser petrosal nerve, accompanied by the superior tympanic artery occupies
the superior tympanic canaliculus, lying lateral to and paralleling the path of
the greater petrosal nerve to the petrous apex. The petrous apex points
anteromedially and is marked by the transition of the intrapetrous to the
intracranial internal carotid artery, orifice of the bony eustachian tube, and,
anterolaterally, ganglion of the trigeminal nerve in Meckel’s cave. The
medial aspect of the temporal bone features the porus of the internal auditory
canal (IAC). Also the petrous apex shows the internal carotid foramen, by
which the internal carotid artery exits the temporal bone (Saleh et al., 1995).
Management of Temporal Bone Malignancy
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Anatomy of The Temporal Bone
The sigmoid portion of the lateral venous sinus runs in a deep sulcus
posteriorly, whereas the superior petrosal sinus runs in the sulcus located at
the junction of the posterior and middle fossa faces of the temporal bone.
The vertically oriented posterior face of the petrosa dominates the posterior
view of the temporal bone as it delimits the anterolateral aspect of the
posterior cranial fossa and lies between the superior and inferior petrosal
sinuses. The porus of the IAC, operculum, endolymphatic fossette cradling
the endolymphatic sac, and subarcuate fossa are the key anatomical features
on this surface (Eshraghi et al., 2001).
Figure 3: Superior view, left temporal bone. The pyramidal shape of the petrous bone is
well shown in this view.
1 – Zygoma, 2 – tegmen, 3 – arcuate eminence, 4 – lesser superficial petrosal canal,
5 – internal carotid artery foramen, 6 – internal auditory canal, 7 – facial hiatus,
8 – petrous apex. (Gulya and Schuknecht, 2007).
The inferior surface of the temporal bone figures prominently in skull
base anatomy as it interfaces with the sphenoid and occipital bones. It
provides attachment for the deep muscles of the neck and is perforated by a
Management of Temporal Bone Malignancy
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Anatomy of The Temporal Bone
multitude of foramina. The jugular fossa, housing the jugular bulb, is
separated from the internal carotid artery by the jugulocarotid crest. The
aperture of the inferior tympanic canaliculus traversed by the inferior
tympanic artery and the tympanic branch of the glossopharyngeal nerve
(Jacobson’s nerve), is located in the jugulocarotid crest, whereas the cranial
aperture of the cochlear aqueduct is located anteromedial to the jugular
fossa. The stylomastoid foramen of the facial nerve is located just posterior
to the styloid process. The occipital artery and the digastric muscle occupy
the temporal groove and the mastoid incisure, respectively, at the medial
aspect of the tip. The jugular foramen is of particular importance in skull
base surgery as it is traversed by the glossopharyngeal (IX), vagus (X), and
spinal accessory (XI) cranial nerves as they exit the skull (Kveton et al.,
1996).
The cochlear aqueduct, carrying the periotic (or perilymphatic) duct,
is an important landmark for the neurootologist. As the cochlear aqueduct
runs from the medial aspect of the scala tympani of the basal cochlear turn to
terminate anteromedial to the jugular bulb, it parallels, and lies inferior to,
the IAC. In addition, cranial nerve IX, the inferior petrosal sinus, and, in
some cases, cranial nerves X and XI can be found immediately inferior to
the lateral terminus of the cochlear aqueduct (Aslan et al., 1998).
Management of Temporal Bone Malignancy
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Anatomy of The Temporal Bone
Figure 4: Inferior view, left temporal bone. This view shows the topographically intricate
inferior surface of the temporal bone.
1 – Inferior petrosal sulcus, 2 – cochlear aqueduct, 3 – inferior tympanic canaliculus,
4 – jugulocarotid crest, 5 – internal carotid artery foramen, 6 – jugular fossa,
7 – sigmoid sulcus, 8 – mandibular fossa, 9 – temporal groove, 10 – mastoid incisure,
11 – mastoid tip, 12 – stylomastoid foramen, 13 – styloid process. (Gulya and
Schuknecht, 2007).
Related Structures
The Tympanic Membrane
The tympanic membrane is irregularly round and slightly conical in
shape; the apex of the cone is located at the umbo, which marks the tip of the
manubrium. In the adult, it is angulated approximately 140° with respect to
the superior wall of the external auditory canal. The vertical diameter of the
tympanic membrane as determined along the axis of the manubrium ranges
from 8.5 to 10 mm, while the horizontal diameter varies from 8 to 9 mm.
Management of Temporal Bone Malignancy
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Anatomy of The Temporal Bone
The malleal prominence, a projection formed by the lateral process of the
malleus, is located at the superior end of the manubrium.
Figure 5: The tympanic membrane. (Gulya and Schuknecht, 2007).
The manubrium is firmly attached to the tympanic membrane at the
umbo and lateral process and is clearly visible throughout its length (the stria
mallearis). The anterior and posterior tympanic striae extend from the lateral
process of the malleus to the anterior and posterior tympanic spines,
respectively. These striae divide the tympanic membrane into larger pars
tensa below, and smaller triangular pars flaccida (or Shrapnell’s membrane)
above.
The superior recess of the tympanic membrane is known as Prussak’s
space. The pars flaccida forms the lateral border of this space as it attaches
superiorly to the bony margins of the notch of Rivinus or tympanic incisura.
The lateral malleal ligament limits this space anterosuperiorly as it extends
Management of Temporal Bone Malignancy
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Anatomy of The Temporal Bone
from the union of the head and neck of the malleus to the periphery of the
notch of Rivinus. Posteriorly, Prussak’s space opens into the epitympanum.
The anterior and posterior malleal folds mark the inferior limit of Prussak’s
space.
The thickened periphery of the pars tensa, the tympanic annulus
(limbus), anchors the tympanic membrane in a groove known as the
tympanic sulcus. The tympanic annulus and sulcus are absent superiorly in
the area of the notch of Rivinus. The pars tensa and pars flaccida differ in
structure. The pars tensa consists of three layers: lateral epidermal layer,
medial mucosal layer, and intermediate fibrous layer, the pars propria
(Gulya and Schuknecht, 2007).
Ossicles
The ossicular chain made up of the malleus, incus, and stapes, serves
to conduct sound from the tympanic membrane to the cochlea. The malleus
is the most lateral of the ossicles, has a head (caput), manubrium (handle),
neck, and anterior and lateral processes. The lateral process has a
cartilaginous “cap” that imperceptibly merges with the pars propria of the
tympanic membrane. The incus, the largest of the three ossicles, is
immediately medial to the malleus. The incus has a body and three
processes: a long, a short, and a lenticular process. The body of the incus
articulates with the head of the malleus in the epitympanum. The short
process of the incus is anchored in the incudal fossa by the posterior incudal
ligament. The long process extends inferiorly, roughly paralleling and lying
posterior to the manubrium. The lenticular process, at the terminus of the
long process, articulates with the stapes. The stapes is the smallest and most
Management of Temporal Bone Malignancy
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Anatomy of The Temporal Bone
medial of the ossicles. Its head articulates with the lenticular process of the
incus, whereas its foot plate sits in the oval window, surrounded by the
stapedo-vestibular ligament. The arch of the stapes, composed of an anterior
and a posterior crura, links the head and the foot plate (Sanna et al., 1980).
Middle Ear Muscles
The tensor tympani muscle, innervated by the trigeminal nerve,
originates from the walls of its semicanal, greater wing of the sphenoid, and
cartilage of the eustachian tube. The tendon of the tensor tympani muscle
sweeps around the cochleariform process and across the tympanic cavity to
attach to the medial aspect of the neck and manubrium of the malleus. The
medial pull of the tensor tympani muscle is ordinarily opposed by the intact
tympanic membrane. The stapedius muscle runs in a vertical sulcus in the
posterior wall of the tympanic cavity adjacent to the facial nerve, from
which it receives its innervation. Its tendon traverses the pyramidal
eminence to attach to the posterior crus, and occasionally the head, of the
stapes (Keles et al., 2009).
Management of Temporal Bone Malignancy
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Anatomy of The Temporal Bone
Figure 6: Schematic view of the middle ear cleft. (Gulya and Schuknecht, 2007).
Middle Ear Spaces
The tympanic cavity is a sagittally oriented slit that lies immediately
medial to the tympanic membrane. Its roof or tegmen, also serves as a part
of the floor of the middle cranial fossa, whereas its irregularly contoured
floor features the jugular bulb and, posteriorly, the root of the styloid
process. The tympanic cavity is in continuity with the eustachian tube
anteriorly and with the mastoid air cells via the aditus ad antrum posteriorly.
It is traversed by the ossicular chain and is lined with a mucosal epithelium.
Planes extended from the tympanic annulus subdivide the tympanic cavity
into a mesotympanum, hypotympanum, protympanum, and posterior
Management of Temporal Bone Malignancy
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Anatomy of The Temporal Bone
tympanic cavity. The epitympanum lies above the plane of the anterior and
posterior tympanic spines. Anteriorly, the mesotympanum is dominated by
the bulge of the semicanal of the tensor tympani muscle; the tympanic
orifice of the eustachian tube is immediately inferior to this bulge.
Posteriorly, the key anatomical feature is the pyramidal eminence and,
lateral to it, the chordal eminence. The medial wall (the surgical “floor” of
the middle ear) features three depressions: the sinus tympani, oval window
niche, and round window niche (Glasscock and Gulya, 2007).
The sinus tympani is defined by the ponticulus superiorly, the
subiculum inferiorly, the mastoid segment of the facial nerve laterally, and
the posterior semicircular canal medially; there is substantial variability in
the posterior extension (surgical “depth”) of the sinus tympani, ranging from
“shallow” to “deep.” The oval window niche, occupied by the stapes
footplate, is located anterosuperior to the ponticulus. The round window
niche can be found posteroinferior to the promontory, the bulge created by
the basal turn of the cochlea (Nomura et al., 1984)
Eustachian Tube
The eustachian tube extends approximately 35 mm from the anterior
aspect of the tympanic cavity to the posterior aspect of the nasopharynx and
serves to ventilate, clear, and protect the middle ear. The lining mucosa of
the tube has an abundance of mucociliary cells, important to its clearance
function. The anteromedial two-thirds of the eustachian tube are
fibrocartilaginous, whereas the remainder is bony. The tympanic orifice is in
the anterior wall of the middle ear, a few millimeters above the floor
(Glasscock and Gulya, 2007).
Management of Temporal Bone Malignancy
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Anatomy of The Temporal Bone
Pneumatization
The extent of pneumatization of the temporal bone varies according to
heredity, environment, nutrition, infection, and eustachian tube function.
There are five recognized regions of pneumatization: the middle ear,
mastoid, perilabyrinthine, petrous apex, and accessory cells. The mastoid
region is subdivided into the mastoid antrum, central mastoid, and peripheral
mastoid. The bony labyrinth divides the perilabyrinthine region into
supralabyrinthine and infralabyrinthine areas. The apical area and the
peritubal area comprise the petrous apex region. The accessory region
encompasses the zygomatic, squamous, occipital, and styloid areas (Nadol
and Schuknecht, 1993).
There are five recognized air cell tracts. The posterosuperior tract runs
at the junction of the posterior and middle fossa aspects of the temporal
bone. The posteromedial cell tract parallels and runs inferior to the
posterosuperior tract. The subarcuate tract passes through the arch of the
superior semicircular canal. The perilabyrinthine tracts run superior and
inferior to the bony labyrinth, whereas the peritubal tract surrounds the
eustachian tube. The anterior petrous apex is pneumatized in only 10 to 15%
of specimens studied. Most often, it is diploic; and in a small percentage of
cases, it is sclerotic (Saim et al., 1996).
Inner Ear
The bony labyrinth houses the sensory organs and soft tissue
structures of the inner ear and consists of the cochlea, three semicircular
canals, and vestibule. The cochlea spirals 2.5 turns about its central axis, and
Management of Temporal Bone Malignancy
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Anatomy of The Temporal Bone
has a height of 5 mm. The base of the cochlea touches the fundus of the IAC
and is perforated (cribrose), allowing for the passage of cochlear nerve
fibers. The apex lies medial to the tensor tympani muscle. The osseous spiral
lamina winds about the modiolus and along the basilar membrane, separates
the scala media (the cochlear duct) from the scala tympani. Adjacent turns of
the cochlea are separated by an interscalar septum (Glasscock and Gulya,
2007).
The three semicircular canals are the lateral (horizontal), superior
(anterior vertical), and posterior (posterior vertical). The three canals are
orthogonally related to one another and arc over a span of 240 degrees. Each
canal has an ampullated limb, measuring 2 mm in diameter, and a nonampullated limb, which is1 mm in diameter. The ampulla is cribrose for
passage of nerve fibers. The non-ampullated limbs of the posterior and
superior canals fuse to form the crus commune. The ampullated and nonampullated limbs all open into the vestibule. The angle formed by the three
semicircular canals is the solid angle, whereas the triangle bounded by the
bony labyrinth, sigmoid sinus, and superior petrosal sinus is known as
Trautmann’s triangle (Carey et al., 2000).
The vestibule is the central chamber of the bony labyrinth and
measures 4 mm in diameter. Its medial wall is marked by depressions for the
saccule (the spherical recess), utricle (the elliptical recess), and cochlear duct
(the cochlear recess). Cribrose areas accommodate nerve fiber access to their
sensory organs. “Mike’s dot” (the macula cribrosa superior) marks the
passage way for superior vestibular nerve fibers to the cristae ampullares of
the lateral and superior semicircular canals. As it corresponds to the extreme
lateral aspect of the IAC, Mike’s dot is an important landmark in transManagement of Temporal Bone Malignancy
15
Anatomy of The Temporal Bone
labyrinthine surgery. There are three fissures of the bony labyrinth. The
fissula ante fenestram is an invagination of the perilymphatic space that is
invariably found extending anterosuperior to the oval window; in the adult,
fibrous tissue and cartilage fill the fissula. The fissula post fenestram is a
perilymphatic evagination that extends posterior to the oval window; it is a
less constant feature of the temporal bone (Gacek et al., 1979).
The membranous (endolymphatic) labyrinth housed within the bony
labyrinth consists of the cochlear duct (scala media), the three semicircular
ducts and their cristae ampullares, the otolithic organs (the utricle and the
saccule), and the endolymphatic duct and sac. The endolymphatic duct
originates in the medial wall of the vestibule. It first parallels the crus
commune and then the posterior semicircular canal as it heads to the
endolymphatic sac, anterior and medial to the sigmoid sinus. The
endolymphatic sac lies approximately 10 mm inferior and lateral to the porus
of the IAC; the sac has an intraosseous portion, which is covered by the
operculum, and a more distal intradural portion (Glasscock and Gulya,
2007).
Internal Auditory Canal (IAC)
The IAC is the bony channel that shelters the superior and inferior
vestibular, cochlear, facial, and intermediate nerves, as well as the
labyrinthine artery and vein, as they course from the posterior cranial fossa
to the labyrinth. On average, the canal measures 3.4 mm in diameter and 8
mm in length; these dimensions display considerable interindividual
variability. The porus is the posterior cranial fossa opening of the canal,
whereas the canal abuts the bony labyrinth at its fundus. At the fundus, the
Management of Temporal Bone Malignancy
16
Anatomy of The Temporal Bone
vestibular, facial, and cochlear nerves are in a constant anatomic relationship
that is determined by the horizontal (falciform) crest and the vertical crest
(“Bill’s bar”) (Naguib et al., 1994).
Figure 7: Internal auditory canal. (Glasscock and Gulya, 2007).
Management of Temporal Bone Malignancy
17
Anatomy of The Temporal Bone
Neuroanatomy
Figure 8: The view of cranial
nerves IX, X, and XI after removal
of the medial wall of the jugular
bulb. A fibrous septum separates
cranial nerve IX from cranial
nerves X and XI. The opening of
the condylar emissary vein (CEV)
is seen in the posteroinferior
portion of the JB. The orifice of the
inferior petrosal sinus (IPS) is seen
posterior to cranial nerves X and
XI. Cranial nerve XII is depicted
exiting its foramen. (Keles et al.,
2009).
Trigeminal and Abducent Nerves
The gasserian ganglion of the trigeminal nerve occupies Meckel’s
cave on the middle cranial fossa face of the temporal bone, anterolateral to
the petrous apex. The abducent (sixth cranial) nerve runs in Dorello’s canal
beneath the posterior petroclinoid (Gruber’s) ligament (Moreano et al.,
1994).
Facial Nerve
The course of the facial nerve is divided into five segments. Its
intracranial segment stretches 24 mm from the pons to the porus of the IAC.
The intracanalicular segment traverses the IAC; at the fundus, it occupies the
anterosuperior quadrant, where it is joined by the nervus intermedius. The
shortest segment is the labyrinthine segment, running 4 mm from the
Management of Temporal Bone Malignancy
18
Anatomy of The Temporal Bone
beginning of the fallopian canal to the geniculate ganglion. The tympanic
segment is roughly 13 mm long and courses in the medial wall of the
tympanic cavity, superior to the cochleariform process and oval window.
The mastoid segment spans the 20-mm distance from the second genu (at the
lateral semicircular canal) to the stylomastoid foramen (Procter et al., 1982).
There are three intratemporal branches of the facial nerve: the greater
petrosal nerve, nerve to the stapedius muscle, and chorda tympani nerve.
The nervus intermedius (nerve of Wrisberg) carries the taste, secretory, and
sensory fibers of the facial nerve. In the IAC, the nervus intermedius runs as
a separate nerve between the facial and superior vestibular nerves. In the
temporal bone, the nervus intermedius is within the facial nerve, occupying
its dorsal aspect in the tympanic segment and its posterolateral aspect in the
mastoid segment. The chorda tympani nerve represents the separation of the
sensory fibers at the inferior mastoid segment (Gacek, 1998).
Cochlear Nerve
The cochlear nerve arises from the spiral ganglion neurons. At the
fundus of the IAC, the cochlear nerve is in the anteroinferior compartment.
It rotates as it heads toward the porus and enters the brainstem a few
millimeters caudal to the root entry zone of the trigeminal nerve (Glasscock
and Gulya, 2007).
Vestibular Nerves
The superior and inferior vestibular nerves occupy the posterior half
of the IAC. The structures innervated by the superior vestibular nerve are the
superior and lateral semicircular canals, utricular macula, and superior
Management of Temporal Bone Malignancy
19
Anatomy of The Temporal Bone
portion of the saccular macula. The inferior vestibular nerve innervates the
inferior saccular macula and, by its posterior ampullary branch, the posterior
semicircular canal. The posterior ampullary nerve separates from the main
trunk of the inferior vestibular nerve a few millimeters from the porus of the
IAC and traverses the singular canal to the posterior canal ampulla
(Eshraghi et al., 2001).
Figure 9: Intracranial
view of the posterior
surface of the petrous
bone showing cranial
nerves V, VIII, IX, X, XI,
and
XII.
The
glossopharyngeal
and
vagal
meatus
are
separated by a dural
septum. Cranial nerve IX
enters the glossopharygal
meatus, whereas cranial
nerve X and cranial nerve
XI enter the vagal meatus.
(Keles et al., 2009).
Management of Temporal Bone Malignancy
20
Anatomy of The Temporal Bone
Vascular Anatomy
Temporal Bone Arteries
The internal carotid artery enters the temporal bone through the
external carotid foramen, located just anteromedial to the styloid process. As
it ascends in its intrapetrous segment, it passes first anterior to the tympanic
cavity and cochlea and then bends (its “knee”) to run medial to the
eustachian tube and inferomedial to the semicanal of the tensor tympani
muscle. The artery climbs to exit the temporal bone at the internal carotid
foramen. Accompanying the artery throughout its intrapetrous course are a
venous and a neural (sympathetic) plexus. The bony shell protecting the
artery is thin (often less than 0.5 mm thick) and can be dehiscent in 6% of
cases (Moreano et al., 1994).
Temporal Bone Veins
The three dominant sinuses of the temporal bone are the sigmoid
(portion of the lateral venous sinus), superior petrosal, and inferior petrosal.
The lateral venous sinus occupies an S-shaped sulcus in the posterior
mastoid (hence the term sigmoid) as it extends from the transverse sinus to
the internal jugular vein. This drainage system on the right is larger than that
on the left in 75% of cases (Glasscock and Gulya, 2007).
The superior petrosal sinus drains the cavernous sinus into the lateral
venous sinus as it runs in the superior petrosal sulcus at the junction of the
posterior and middle fossa dural plates. The inferior petrosal sinus courses in
the petro-occipital suture line. It drains the cavernous sinus into the jugular
bulb (Gacek et al., 1992).
Management of Temporal Bone Malignancy
21
Pathology
of
Temporal Bone Malignancy
Pathology of Temporal Bone Malignancy
The variability of malignant lesions that could arise within the temporal
bone is due to the different histological characters of the tissues involved.
The external ear consists of the auricle and the external auditory canal; the
outer aspect of the tympanic membrane defines its innermost extent. The pinna is
mainly composed of a shell of fibrocartilage and is fixed to the skull by skin,
cartilage, muscle, and ligamentous tissue. The pinna and external auditory canal
are lined by keratinising squamous epithelium with accompanying cutaneous
adnexal structures (such as hair follicles and sebaceous glands) (Devaney et al.,
2005).
Furthermore, the outer portion of the external canal contains variants of the
apocrine gland known as ceruminous glands. The pinna and external auditory canal
are, in turn, supported by fibrofatty soft tissue, elastic cartilage, and bone. The
middle ear is lined by ciliated respiratory-type epithelium (eustachian tube) and by
a single layer of cuboidal-to-flattened epithelium (tympanic cavity and mastoid
cavity). The inner ear contains both the labyrinth and the eighth cranial nerve (the
vestibulocochlear nerve), as it runs through the internal auditory canal. The sensory
cells of hearing and balance are found in the labyrinth, bathed in endolymph (a
hybrid of extracellular fluid and cerebrospinal fluid) (Devaney et al., 2005).
Management of Temporal Bone Malignancy
22
Pathology of Temporal Bone Malignancy
The malignant tumors that could arise from the temporal bone are
Malignant neoplasms of the external ear
 Squamous cell carcinoma
 Basal-cell carcinoma
 Malignant melanoma
 Merkel-cell carcinoma
 Adenexal carcinoma (including ceruminous adenocarcinoma, adenoid cystic
carcinoma & mucoepidermoid carcinoma)
 Angiosarcoma (including both conventional angiosarcoma and Kaposi’s
sarcoma)
 Lymphoma
Malignant neoplasms of the middle and inner ear
 Endolymphatic-sac tumor (aggressive papillary tumor)
 Squamous cell carcinoma
 Adenocarcinoma
 Rhabdomyosarcoma
 Lymphoma, multiple myeloma, and plasmacytoma
 Metastatic carcinoma
(Barnes et al., 2005)
Management of Temporal Bone Malignancy
23
Pathology of Temporal Bone Malignancy
Squamous cell and basal cell carcinoma
Cutaneous squamous carcinomas and basal cell carcinomas are the most
common malignant carcinomas affecting the temporal bone. Although there are
distinct
light-microscopic
differences
between
squamous
and
basal-cell
carcinomas, the two are considered together here as non-melanomatous cutaneous
carcinomas. In the pinna, basal cell carcinomas are about four times more common
than squamous carcinomas; however, in the external auditory canal the ratio is
reversed. Squamous and basal-cell carcinomas are mainly diseases of older men,
diagnosed on average when they are in their 70s (Ahmad &Gupta, 2001).
Both carcinomas are closely associated with previous actinic damage to the
skin (through exposure to ultraviolet radiation) when they arise in the pinna.
However, this association is not seen in lesions of the external auditory canal;
squamous cell carcinomas of the external canal are frequently preceded by a few
years’ history of a chronic draining otorrhea as in chronic suppurative otitis media
which was accepted in the older literature as an obvious etiologic factor (Gacek et
al., 1998).
The gross appearance of basal cell carcinoma is usually one of a pearly waxlike nodule that eventually ulcerates. Twenty-five percent of basal cell carcinomas
of the pinna are of the morphea type. The importance of this variety is that
although the edge of the tumor tends to infiltrate subcutaneously, this cannot be
recognized clinically or on gross pathological examination. The classical and most
frequent form of basal cell carcinoma is composed of solid masses of cells, which
Management of Temporal Bone Malignancy
24
Pathology of Temporal Bone Malignancy
are seen to be arising from the basal layers of the epidermis or the outer layers of
the hair follicles (Vantuchova& Curik, 2006).
The cells are uniform with basophilic nuclei and little cytoplasm. At the
periphery of the neoplastic lobules the cells tend to be palisaded. Squamous cell
differentiation is also common. The cell groups are splitted by hyaline fibrous
tissue, so that the carcinoma appears compressed into thin strands; is referred to as
the morphea type of basal cell carcinoma. The suggestion that tumors with this
histology have a worse outlook is probably related to their tendency towards
insidious infiltration. However, when immunohistochemical assessment for Ki-67
antigen (MIB1 in paraffin sections) is performed on basal cell carcinomas, those
tumors that recur have been shown to possess a higher proportion of cells positive
for that antigen than those that do not (Heiligenhaus et al., 1996)
The morphea type of basal cell carcinoma is not an aggressive neoplasm and
in at least 90% of cases a 3-year cure can be easily achieved by surgical excision.
In a few cases repeated recurrences with deep extension to the middle ear, mastoid
and even cranial cavity may, however, take place; although metastasis is rare
(Vantuchova& Curik, 2006)
The majority of squamous cell carcinomas of the external ear arise in the
pinna; a lesser number arise in the external canal. A plaque-like or even polypoid
mass may be felt or even seen in the pinna. The appearances of the canal lesions
are those of a mass, sometimes warty, occluding the lumen and invading deeply
into the surrounding tissues. There may be dissolution of the tympanic membrane
with invasion of the middle ear. It usually shows significant degrees of
keratinisation. In the cases with a canal origin evidence of origin from canal
Management of Temporal Bone Malignancy
25
Pathology of Temporal Bone Malignancy
epidermis is usually present. In cases arising deep within the ear canal there is
usually a concomitant origin from middle ear epithelium and dissolution of the
tympanic membrane. The neoplasm may be so well differentiated that it can be
confused with benign papilloma. The association of a well-differentiated squamous
carcinoma with marked desmoplasia may also delay the correct diagnosis. The
verrucous form of squamous cell carcinoma has been seen in the external ear (Sjo
et al., 2001).
Metastatic spread of squamous cell carcinoma of the pinna and external
auditory meatus to lymph nodes is unusual. Squamous cell carcinoma of the
external canal is an aggressive disease with a high propensity towards local
recurrence (Prabhu et al., 2009).
Both squamous cell carcinomas and basal cell carcinomas can metastasize.
Although squamous cell carcinomas give rise to metastases much more commonly
than basal cell carcinomas; distant metastases from squamous cell carcinoma of the
ear are rare (Sasaki, 2001).
Malignant Melanoma
Melanotic neoplasms are unusual in the external ear. They usually arise in
the auricle; origin in the external canal is extremely unusual. Malignant melanoma
of the external ear is a highly aggressive malignant disease. By the time of the
diagnosis, patients with malignant melanoma usually are at an advanced stage of
the disease (Merchant & Weinstein, 2003).
Management of Temporal Bone Malignancy
26
Pathology of Temporal Bone Malignancy
It is likely that cervical and parotid gland lymph nodes will be involved
when malignant melanoma of the external ear is first diagnosed (Schuster &
Seregard, 2003).
The external ear accounts for about 10% of all head and neck melanomas.
As elsewhere in the body, melanomas of the external ear are associated with
previous actinic damage. Men are more affected than women (ratio two to one or
three to one); the average age is in the 50s, and most present with a nodular or
flattened pigmented lesion. Crucial outcome factors include clinical stage at initial
presentation and the microscopical thickness of the lesion (Pockaj et al., 2003).
These tumors are aggressive and can spread to regional lymph nodes early in
the course of disease. A major drawback is posed by the variability of lymphatic
drainage patterns from the ear; the upper cervical region and the lower tail of the
parotid gland are most commonly cited as regional draining regions for the
lymphatics of the ear (Cole et al., 2003).
Merkel-cell carcinoma
Merkel-cell carcinomas (cutaneous neuroendocrine carcinomas) are rare,
slow-growing subcutaneous nodules that develop in sun-exposed areas in elderly
patients, presenting, on average, in their 70s; about equal numbers of men and
women develop these tumors. Although initial reports suggested that these might
be indolent tumors, subsequent experience has shown that they have a propensity
for local recurrence locally and metastasis, both to regional lymph nodes and to
distant sites (including lung and liver). Some investigators have reported a
Management of Temporal Bone Malignancy
27
Pathology of Temporal Bone Malignancy
mortality rate slightly above 50% for Merkel-cell carcinomas, which is higher than
for melanomas (Litofsky et al., 1998).
The designation of these neoplasms as Merkel-cell tumors indicates the
supposed derivation of these lesions from cutaneous neuroendocrine cells (the
Merkel cells). Pathological diagnosis can be complicated by the resemblance of
this lesion to both lymphoma and metastatic small-cell carcinoma of pulmonary
origin. Immunohistochemical analysis can distinguish between lymphoma and
Merkel-cell tumor. (Lehrer et al., 2004).
Figure 10: Merkel-cell carcinoma of the
antitragus in a 72-year-old man. Tumor cells
are round, undifferentiated, and arranged in
sheets and cords. Despite superficial
location, the tumor has a propensity for
spreading to regional lymph nodes and to
visceral sites (including lung and liver)
(Devaney et al., 2005).
Adenexal carcinoma of the ear
The mechanism by which the tumor develops is not clearly understood, there
are four suspected etiopathogenetic hypotheses: those originating from the
seromucinous glands because of functional alterations of the mucosal epithelium,
those caused by chronic irritation that causes squamous metaplasia of the mucosa,
seromucinous and minor salivary glands implanted in the ear during
Management of Temporal Bone Malignancy
28
Pathology of Temporal Bone Malignancy
embryogenesis, and finally those caused by secondary invasion of a tumor located
in an adjacent primary site (Soh et al., 1996).
The two most common malignant glandular neoplasms of the external ear
are seromucinous adenocarcinoma and adenoid cystic carcinoma (Mansour et al.,
1992).
Seromucinous adenocarcinomas arise in adults, with patients presenting on
average in their 50s. Although in some cases a deceptively bland appearance on
light microscopy suggests that these are benign tumors, seromucinous
adenocarcinomas are stubbornly persistent lesions, with a local recurrence
approaching 50%. Although these are locally aggressive tumors, they only rarely
metastasize to regional lymph nodes or the lungs (Tzagaroulakis et al., 2003).
The neoplasm possesses a glandular structure with evidence of apocrine
differentiation, but the glands show loss of a myoepithelial layer and the cells are
markedly atypical with increased mitotic activity (Lassaletta et al., 2003).
The average age at diagnosis of an adenoid cystic carcinoma falls
somewhere in the patient’s 50s; occurrence in women predominates over that in
men by a ratio of two to one. Many adenoid cystic carcinomas are painful lesions.
In common with some seromucinous adenocarcinomas of the external ear, most
adenoid cystic carcinomas of the external ear have a bland cytological appearance
on light microscopy; this appearance belies their aggressive character when their
behavior is tracked over long periods. Although 5-year survival for patients with
adenoid cystic carcinomas (arising in all sites) is over 75%, long-term follow-up
studies show that 20-year survival is as low as 10% or 15%. It has insidiously
Management of Temporal Bone Malignancy
29
Pathology of Temporal Bone Malignancy
infiltrative character, which typically shows perineural invasion with far more
expansive microscopic extension than had been suggested by physical examination
or imaging studies (Kokemueller et al., 2004).
Local extension to involve the adjacent parotid gland is common. Nodal
metastases are not commonly encountered early in the course of disease. Distant
metastatic deposits of adenoid cystic carcinoma commonly develop later in the
course of disease. Sites of late metastasis include the lung, lymph nodes, and the
skeletal system (Alcedo et al., 2004).
Mucoepidermoid carcinomas are malignant tumors that frequently originate
in the major and minor salivary glands (Soh et al., 1996).
The seromucinous glands are known to be situated in the deep dermis of the
external auditory canal. Under histological examination mucoepidermoid
carcinoma appear to be composed of scattered solid and cystic mucinous areas. In
the solid parts, the cells are arranged in nests, are tubular in structure, and have
different characteristics very similar to those of mucous squamous cells, whereas
other cells have intermediate histopathological characteristics. According to the
percentage of the different cells there is a low-, medium-, or high-grade
malignancy (Devaney et al., 2005).
In low-grade tumors, there is a higher percentage of mucous cells, and in
medium-grade tumors, there is an equal percentage of glandular and epithelial
cells. The histological diagnosis of mucoepidermoid carcinoma is often difficult
and not always completely reliable. High-grade mucoepidermoid carcinoma are
very similar to poorly differentiated squamous carcinoma except for the fact that
Management of Temporal Bone Malignancy
30
Pathology of Temporal Bone Malignancy
the former has intermediate and mucin-secreting cells, a difference that gives a
useful indication in the histological diagnosis. Grossly they appear as solid reddish
masses that are variable in shape (usually irregular) and may be located in any part
of the external auditory canal (Kim et al., 2001).
Figure 11: Glandular tumors (microscopic picture)
a. Seromucinous adenocarcinoma. An intact surface epithelium is subtended by an
infiltrating "biphasic" neoplastic proliferation separated by dense fibrosis.
b. Seromucinous adenocarcinoma demonstrating decapitation secretion in the center gland,
while the remarkably atypical cells are seen in an "infiltrative"growth pattern. Note the
mitotic figure in the upper right corner.
c. Adenoid cystic carcinoma. The overall cribriform ("Swiss-cheese") pattern is seen on
both the low power and with the inset.
d. Mucoepidermoid carcinoma both the epidermoid and mucous components are clearly
shown. (Devaney et al., 2005).
Management of Temporal Bone Malignancy
31
Pathology of Temporal Bone Malignancy
Sarcomas of the ear
Rhabdomyosarcoma is a soft tissue malignant tumor of skeletal muscle
origin. It affects children much more common than the adults. Several hypotheses
have been set forth concerning the cellular origins of rhabdomyosarcoma tumors.
They may originate from either totipotential mesenchymal cells, from immature
myoblastic tissue, or from muscles of the middle ear (Ries et al., 1999) .
Grossly, the tumor is lobulated and dark red with a haemorrhagic cut
surface. Microscopically, rhabdomyosarcoma is composed primarily of small,
anaplastic, round and spindle-shaped cells exhibiting hyperchromic nuclei and
granular acidophilic cytoplasm. There are four histological subtypes of
rhabdomyosarcoma: embryonal, alveolar, botryoid, and pleomorphic. The
embryonal subtype remains the most commonly found subtype in the head and
neck region; however it is not uncommon to find a mixture of subtypes in
individual cases (Parham et al., 2001; Newton et al., 1995).
Embryonal rhabdomyosarcoma has high cytologic variability, which
represents several stages of skeletal muscle morphogenesis. They may range from
highly differentiated neoplasms containing rhabdomyoblasts with large amounts of
eosinophilic cytoplasm and cross striations similar to that of poorly differentiated
tumor cells. Desmin and muscle specific actin are the typical stains used to identify
rhabdomyosarcoma ( Sbeity et al., 2007).
Immunohistochemistry remains the current ancillary method of choice in the
pathological evaluation of small blue round-cell tumors. In at least 20% of cases of
rhabdomyosarcoma, it is considered an essential factor in the final and/or
Management of Temporal Bone Malignancy
32
Pathology of Temporal Bone Malignancy
differential diagnosis of the malignancy. The newer immune-stains (antimyogenin,
MyoD1) generated against intranuclear myogenic transcription factors offer
pathologists the best hope for improving the sensitivity and specificity of
rhabdomyosarcoma diagnosis ( Morotti et al., 2006).
Figure 12: Embryonal rhabdomyosarcoma:
undifferentiated primitive cells in a myxoid
background. Red cells are differentiating
rhabdomyoblasts with one mature cell (arrow)
(Sbeity et al., 2007).
Chondrosarcoma of the temporal bone is an uncommon neoplasm. It is a
malignant tumor of cartilage forming tissues, and can be divided into two major
types based on microscopic criteria; conventional chondrosarcoma and
chondrosarcoma variants. The latter type is further divided into; clear cell, myxoid,
and mesenchymal subtypes (Raghu et al., 2004).
Sites of origin within the temporal bone are the petrous apex, mastoid and
tympanic portion. Because the embryology of the petrous apex and mastoid
involves
endochondral
development
(within
cartilage)
rather
than
intramembranous development (within a membrane), chondrosarcomas arise from
congenital cell rests within these regions. Poorly differentiated lesions behave
more aggressively than better-differentiated tumors (Raghu et al., 2004).
Management of Temporal Bone Malignancy
33
Pathology of Temporal Bone Malignancy
Figure 13: Chondrosarcoma
(A) Histological findings: small cells and a few chondrocytes can be seen embedded in a myxoid
area.
(B) High-power view showing some binucleated cells (arrows) (Yagisawa et al., 2007).
Cutaneous angiosarcoma is a rare form of sarcoma, of which about half are
found in the head and neck area. They present as red–purple macular eruptions that
might be mistaken for bruising, or as nodular lesions. They are ill defined, and
their margins are therefore difficult to assess. Male to female ratio is 2: 1. Children
are diagnosed with angiosarcomas occasionally, but the average age at presentation
is about 50 years (Pawlik et al., 2003).
Angiosarcomas are very aggressive lesions. Distant spread to lymph nodes,
the lungs, and the liver commonly develops in these patients. The vague
presentation can delay clinical recognition of an angiosarcoma. On examination,
even skilled pathologists sometimes have difficulty in discerning the presence or
absence of angiosarcoma in biopsy samples of surgical margins. Although some
Management of Temporal Bone Malignancy
34
Pathology of Temporal Bone Malignancy
angiosarcomas are well differentiated on light microscopy (and thus are
recognizable as vascular in nature), other angiosarcomas are more difficult to
identify as vascular. Immunohistochemical studies with antibodies such as (CD34,
CD31, Fli-1, LYVE-1, and FKBP12) can help resolve diagnostic dilemmas in the
diagnosis of such poorly differentiating tumors (Budd, 2002).
Before the AIDS epidemic, Kaposi’s sarcoma of the ear was a curiosity
occasionally encountered as a minor element of systemic disease, but not in itself a
source of substantial disease burden (Babuccu et al., 2003).
The AIDS epidemic has, however, changed this situation, and auricular
Kaposi’s sarcoma lesions are now encountered regularly. They can even be the
presenting sign of the underlying immunodeficiency. Overall, Kaposi’s sarcoma is
the most commonly encountered neoplasm in patients with AIDS. Four clinical
groupings of Kaposi’s sarcoma are now recognized: chronic (classic,
Mediterranean); lymphadenopathic (African); transplantation-associated; and
AIDS-related (epidemic). Discovery of the association of Kaposi’s sarcoma with
infection with human herpes virus 8 suggests an aetiological role for this virus in
this neoplasm. As is the case with some angiosarcomas, the light microscopic
appearance of Kaposi’s sarcoma (particularly early lesions) can be reminiscent of
several other lesions, ranging from a non-specific reactive process to fibrosarcoma.
Immunohistochemical studies with antibodies such as Fli-1, LYVE-1, D2-40, and
human-herpesvirus-8-latent nuclear antigen 1 might help unravel the nature of
perplexing cases. Kaposi’s sarcoma lesions present as red–purple or brown–red
plaques or as nodules of the external ear (Delbrouck et al., 1998).
Management of Temporal Bone Malignancy
35
Pathology of Temporal Bone Malignancy
Figure 14: Kaposi’s sarcoma of a 23-year-old man
with AIDS; The light-microscopic pattern is
dominated by proliferation of uniform spindle cells
arranged in fascicles, with many interspersed
erythrocytes (Devaney et al., 2005).
Endolymphatic sac tumor
Endolymphatic sac tumor is a slow-growing, locally aggressive neoplasm
that originates from the epithelium of the endolymphatic sac and duct. It is a
recently recognized neurotologic disease entity characterized by the presence of a
destructive papillary cystic adenomatous tumor of the temporal bone.
Endolymphatic sac tumors are known to occur more frequently in patients with
Von Hippel Lindau disease but these tumors also appear sporadically in patients
who do not have that disease (Wada et al., 2006).
The ratio of endolymphatic sac tumors have occurred sporadically in
patients who do not have Von Hippel Lindau disease compared with patients who
do is (103 versus 46). Much information that has been learned recently regarding
the genesis of these lesions has been via an understanding of the genetics and
molecular biology that result from a mutation in the Von Hippel Lindau tumor
suppressor gene. Von Hippel Lindau disease is an autosomal dominant
multisystemic disorder characterized by cerebellar hemangioblastomas, retinal
angiomas, and renal cysts, clear cell renal carcinomas, and other visceral tumors.
Von Hippel Lindau disease has a prevalence of 1 in 39,000 people. The Von
Management of Temporal Bone Malignancy
36
Pathology of Temporal Bone Malignancy
Hippel Lindau gene product is a tumor suppressor that when lost or mutated results
in a loss of inhibition to cell growth and can lead to neoplasms such as
endolymphatic sac tumor. The Von Hippel Lindau gene product protein is
important in the regulation of hypoxia inducible factor–1a, which controls
angiogenesis and cell metabolism (Bambakidis et al., 2004; Jensen et al., 2004).
The growth of endolymphatic sac tumor seems to advance slowly, over the
course of years. As the tumor grows, it takes on the appearance of an infiltrative,
poorly circumscribed neoplasm composed of cuboidal to low-columnar epithelial
cells disposed in a fibrous stroma and arranged either in papillary patterns or cystic
spaces that contain protein like material resembling thyroid follicles. Before
recognition of the endolymphatic sac tumor entity, the finding of these lesions in
the temporal bone and cerebellopontine angle was thought by some to be the result
of ectopic choroid plexus papillomas because of the similar appearance of
aggressive papillary tumors (later believed to be endolymphatic sac tumors) of the
temporal bone and tumors of the choroids plexus. Nearly all endolymphatic sac
tumor express cytokeratin, vimentin, and epithelial membrane antigen, and most
stain positive for S-100 and neuron-specific enolase (Lonser et al., 2004; Kim et
al., 2005).
Management of Temporal Bone Malignancy
37
Pathology of Temporal Bone Malignancy
Figure 15:
Histopathologic examination of
endolymphatic sac tumor revealed papillar pattern
and scattered follicular structures (Yilmaz et al.,
2008).
Multiple myeloma, and plasmacytoma of the middle and inner ear
Haemopoietic lesions, such as lymphoma, multiple myeloma, and
plasmacytoma, are rare lesions of the middle and inner ear. Most affected patients
are adults, although occasional cases in children have been described (Lang et al.,
2003).
Plasmacytoma is a rare clinical entity, arising from malignant proliferation
of B-cell line, and belongs to non-Hodgkin lymphomas. It derives as a clone of
malignant plasma cells. The malignancies considered as plasma cell tumors are
extramedullary plasmacytoma, solitary plasmacytoma of the bone, multifocal form
of multiple myeloma, multiple myeloma and plasmablastic sarcoma (Dimopoulos
et al., 2002).
Extramedullary plasmacytomas are rare tumors, encompassing only 4% of
all plasma cell malignancies. According to the origin of neoplastic cells, the
solitary plasmacytomas are subdivided into solitary bone and extramedullary
plasmacytoma. The solitary bone plasmacytoma derives from bone marrow and is
Management of Temporal Bone Malignancy
38
Pathology of Temporal Bone Malignancy
characterized by bone erosion, whereas the extramedullary one arises in
submucosal layer of tissues, without bone involvement (Liebross et al., 1999).
Plasmacytomas of the temporal bone are structurally no different than those
that occur in other sites. They are constituted by uniform sheets of plasma cells
supported by a sparse matrix. Typically, these plasma cells are either poorly or
well differentiated, but occasionally a mixed population of small, mature plasma
cells and large, immature, multinucleated plasmacytoid cells is present. Amyloid
deposits may occasionally be noted. Immunoperoxidase staining shows a
monoclonal population of plasma cells, differentiating plasmacytoma from other
neoplastic
processes.
The
absence
of
inflammatory
cells
distinguishes
plasmacytoma from reactive processes such as plasma cell granuloma (Panosian et
al., 1994).
Figure 16: Plasma cell tumor
A. Submucosal solid lymph plasma cells and focal infiltrations of neoplastic plasma cells
(hematoxylin-eosin stain).
B. Solid summations of neoplastic plasma cells (hematoxylin-eosin stain) (Markou et al.,
2009).
Management of Temporal Bone Malignancy
39
Pathology of Temporal Bone Malignancy
The first essential approach of the differential diagnosis of the
Extramedullary plasmacytomas is the exclusion of other plasma cell dyscrasias and
especially of dissemination of the disease into multiple myeloma. This systematic
examination requires complete blood count with white cell differential, erythrocyte
sedimentation rate, serum calcium, phosphorous, blood urea nitrogen, creatinine,
serum and urine protein electrophoresis, bone marrow biopsy, chest radiograph,
and a radiographic skeletal survey (Markou et al., 2009).
Lymphoma of the temporal bone
Although lymphomas account for the largest number of nonepithelial
malignancies of the head and neck, these lymphoproliferative neoplasms seldom
present in the temporal bone area. The temporal bone lymphomas generally present
either as metastatic focus from distant primaries or encroachment from contiguous
locations. Sporadic cases of primary extranodal lymphoproliferative malignancies
originating in the temporal bone area have been reported; potential sites of origin
include the middle ear mastoid internal auditory canal and external auditory canal
(Fish et al., 2002).
Lymphomas typically present as solid, malignant neoplasms that arise from
lymphocytes and their respective precursor cells. These malignancies are generally
grouped into one of two major categories: Hodgkin disease and non- Hodgkin's
lymphoma (Wanamaker et al., 1997).
Extranodal involvement although rare in Hodgkin's disease may be present
in as many as 30% of patients with non-Hodgkin's lymphoma. Although
Management of Temporal Bone Malignancy
40
Pathology of Temporal Bone Malignancy
uncommon, a number of cases of temporal bone lymphomas have been reported, in
most of them the lymphoma was metastatic (Nathu et al., 1999).
Metastatic carcinoma of temporal bone
Neoplasms which originate from sites other than the structures of the ear i.e.
external auditory canal, middle ear and temporal bone may metastasize via blood
or lymphatic channels from non-contiguous sites or spread directly from a
contiguous site by invasion of surrounding tissues or extension through existing
channels (Miro Castillo et al., 2000).
Metastasis through direct extension into the temporal bone occurs from the
upper aero-digestive tract via the eustachian tube and middle ear, and from the
posterior fossa of the skull via the internal auditory canal. Invasion of bone and
soft tissue with extension into the base of the skull, external auditory canal, middle
ear and mastoid occurs with paragangliomas and malignancies of the parotid gland
(Gloria-Cruz et al., 2000).
Breast is by far the most common malignancy metastasizing to the temporal
bone, followed by lung/bronchus, prostate, melanoma and thyroid. Blood borne
metastases tend to localize to the petrous ridge and mastoid and are usually
bilateral, multiple and associated with metastases to other bones (Nelson et al.,
1991).
Management of Temporal Bone Malignancy
41
Pathology of Temporal Bone Malignancy
Patterns of Spread
The local extent of primary disease at presentation is the most important
determinant of survival (Moffat et al., 2000).
Tumors of the temporal bone can erode directly through bone or along
preformed vascular and neural pathways. Anterior spread from the external
auditory canal to the temporomandibular joint, parotid gland, or infratemporal
fossa occurs directly through the thin bone of the external auditory canal, the
petrosquamous suture, a patent foramen of Huschke or the fissures of Santorini in
the cartilaginous external auditory canal. Medial spread through the tympanic
membrane or posteriorly into the mastoid allows access to the entire air cell system
of the temporal bone to expose the otic capsule, posterior fossa dura, sigmoid
sinus, eustachian tube, and carotid artery (Pensak et al., 1996).
Inferior extension can involve the jugular foramen and upper neck
compartments. Superior spread erodes the tegmen tympani with potential
involvement of the dura and temporal lobe. Large tumors can spread along all
pathways (Pensak et al., 1994).
Management of Temporal Bone Malignancy
42
Pathology of Temporal Bone Malignancy
Figure 17: Coronal anatomy of pathways of spread of primary cancer of the external
auditory canal. Cancer can spread (1) anteriorly through the cartilaginous canal
into the parotid gland, (2) through the concha into the postauricular sulcus, (3)
through the tympanic membrane into the middle ear, (4) posteriorly into the
mastoid, (5) into the anterior mesotympanum to the carotid artery and Eustachian
tube, (6) into the inner ear through the round window or otic capsule, (7) along the
extratemporal facial nerve into the infratemporal fossa, and (8) inferomedially into
the jugular fossa, carotid artery and lower cranial nerves. The involvement of
upper deep cervical lymph nodes is very uncommon so routine neck dissection is
not recommended. Distant metastases are rare but have been reported in the liver,
brain, lung, and bones (Moody et al., 2000).
Management of Temporal Bone Malignancy
43
Pathology of Temporal Bone Malignancy
Staging Systems
Unfortunately, there are no universal staging systems for cancers of the
external auditory canal, middle ear, and mastoid. Three current systems are
summarized in the following table.
Stage
T1
T2
T3
T4
Modified Pittsburgh (2000)
The Otology Group (2000)
Clark/Stell (1991)
Tumor limited to the external auditory canal Disease confined to external Tumor limited to site
without bony erosion or evidence of soft auditory
canal
including of origin
tissue involvement
spread from auricular cancer
to canal and confined to it
Tumor with limited to external auditory canal Disease spread from external
bone erosion (not full thickness) or limited auditory canal to one or any
(<0.5 cm) soft tissue involvement
combination
of
the
following:Temporomandibular
joint Parotid Infratemporal
fossa
Tumor
extending
beyond site of origin
indicated by facial
palsy or radiologic
evidence of bone
destruction
Spread of disease from
Tumor eroding the osseous external auditory external auditory canal to one
canal (full thickness) with limited (<0.5 cm) or any combination of the
soft tissue involvement, or tumor involving following: Middle ear Mastoid
the middle ear or mastoid
Facial nerve and fallopian
canal
Involvement
of
parotid
gland,
temporomandibular
joint,
or
skin
(extracranial spread)
Tumor eroding the cochlea, petrous apex,
medial wall of the middle ear, carotid canal,
jugular foramen, or dura, or with extensive
soft tissue involvement (>0.5 cm), such as
involvement of TMJ or styloid process, or
evidence of facial paresis
Spread of disease to any one Involvement of dura
of the following:
or
skull
base
(intracranial spread)
Dura, Jugular bulb, sigmoid
sinus, Carotid artery or
Petrous apex
(Barrs, 2001)
Management of Temporal Bone Malignancy
44
Pathology of Temporal Bone Malignancy
According to Modified Pittsburgh (2000) staging system proposed for the
external auditory canal and middle ear
N-status; Involvement of lymph node is a poor prognostic finding and
automatically places the patient in an advanced stage (i.e., Stage III [T1N1] or
Stage IV [T2, T3, T4, N1] disease).
M-status; Distant metastasis indicates a very poor prognosis and
immediately places the patient in the stage IV category. In the absence of
metastatic lymph nodes or distant metastases, T-status defines the overall clinical
stage of the patient (Barrs, 2001).
Management of Temporal Bone Malignancy
45
Clinical Assessment
of
Temporal Bone Malignancy
Clinical Assessment of Temporal Bone Malignancy
Unfortunately, the diagnosis of temporal bone malignancy is seldom
made early. The unique anatomy of the temporal bone contributes to this
fact. The majority of cancers of the ear have involved bone by the time a
diagnosis is made. Carcinomas of the external and middle ear appear to
occur mainly in elder people, and the males seem to be more predisposed.
The mean age was reported to be over 60 years in some studies. However
auricular carcinomas appear in much elder patients (Moody et al., 2000;
Pfreundner et al., 1999).
The age incidence changes in other types of tumors as in sarcomas
specially rhabdomyosarcoma. It is not a tumor of adults; most
rhabdomyosarcomas of the ear develop in children. The average age at
diagnosis is about 4 years; adolescents or young adults are affected less
commonly. So when one encounters the symptoms and clinical findings
suggestive of cancer in the pediatric age group, the possibility of embryonal
rhabdomyosarcoma should be considered. Sarcomas here are generally
considered to be more frequent than carcinoma in the pediatric age group.
Needless to say, biopsy is the modality on which we depend for conclusive
diagnosis (Durve et al., 2004; Hawkins et al., 2001).
Also in the case of endolymphatic sac tumor that arises in association
with Von Hippel–Lindau disease occurs in young age group. While if it is
not associated with Von Hippel–Lindau disease, it occurs in older age
groups (Bambakidis et al., 2004).
Management of Temporal Bone Malignancy
46
Clinical Assessment of Temporal Bone Malignancy
The most frequent symptoms associated with malignant disease of the
temporal bone are chronic otorrhea, hearing loss and pain. Later symptoms
are bleeding, vertigo, facial paralysis, and the presence of a mass protruding
from the external canal. These symptoms depend upon several factors such
as the presence of infection, the actual site of origin, the activity of the
tumor, and the size of the tumor (Leonetti et al., 1996).
Chronic otorrhea is such a common finding associated with middle ear
malignancy that it is suspected to be one of the etiologic factors. On the
other hand, it is extremely rare to find cancer of this region without evidence
of infection and with an intact tympanic membrane.
Figure 18: Photograph of the
left ear shows a tumor extruding
from the External auditory canal
(Takahashi et al., 2002)
Multiple fibrous polyps are not
infrequently seen. The presence of highly vascular granulomatous tissue
must be viewed with suspicion. Its frequent appearance in benign chronic
ears may lower one's guard in diagnosing malignant disease. So, many
patients with temporal bone malignancy their first presentation is long
history of chronic ear not responsive to medical treatment. For that it is
recommended to take biopsy from any granulomatous tissue that does not
Management of Temporal Bone Malignancy
47
Clinical Assessment of Temporal Bone Malignancy
respond to a reasonable course of local and systemic therapy (Aarena &
keen 1988)
Carcinoma of the temporal bone can present as bloody otorrhea
without history of chronic ear. Also the patient may mislead necrotic tissue
or tumor mass in the ear canal as ear wax (Moody et al., 2000).
There are certain symptoms and signs suggestive of local extension
and spread of the tumor;
as uncontrollable pain which may radiate to the
face. The development of facial nerve paralysis due to involvement of facial
nerve in its bony canal in the medial wall of the middle ear. Also the
presence of severe conductive hearing loss, unilateral sensorineural hearing
loss, otitis media, vertigo, taste dysfunction, may indicate invasion into the
middle ear, eustachian tube, and otic capsule. The presence of Horner's
syndrome, transient ischemic attacks, or syncope may indicate involvement
of the internal carotid artery (ICA). The presence of seizures, dysphasia, and
other cognitive deficits warrant investigation for intracranial spread of
tumor. There may be tenderness in the region of the mastoid due to
infiltration of cell system of the mastoid bone and trismus from pterygoid
muscle involvement. Swelling in the parotid region due to spread to the
parotid gland. A late feature is the jugular foramen syndrome producing
paralysis of the tongue, palate and larynx (Yeung et al., 2002).
However, the patient should be examined carefully for physical
evidence of a mass in the neck, soft palate and post auricular region. An
audiogram is obtained to establish the type and degree of hearing loss. The
status of the hearing is important because preservation of hearing is possible
only if lateral resection of the temporal bone is performed (Hirsch B. et al.,
2008).
Management of Temporal Bone Malignancy
48
Radiological Diagnosis
of
Temporal Bone Malignancy
Radiological Diagnosis of Temporal Bone Malignancy
Computed Tomography (CT) of The Temporal Bone
CT scanning became widely used in the 1970s. Because of the
exquisite bony detail it can provide, it is beneficial for assessing temporal
bone and skull base lesions. The most recent technologic advance is the
advent of multidetector (multislice) scanners (Butler et al., 1999).
Standard Spiral CT
CT scanning of the skull base should be tailored for the anatomic
region under consideration. Spiral (helical) CT scanning is rapidly replacing
conventional dynamic CT (slice-by-slice acquisition) in most medical
centers. Spiral CT, which involves the continuous rotation of the x-ray tube
and detector row as the patient translates through the scanning gantry,
permits rapid scanning of large volumes of tissues and usually reduces the
amount of needed intravenous contrast material, eliminates much of the
motion artifact seen with slower scans, and allows multiplanar and threedimensional (3D) reconstructions. Moreover, multirow detector technology,
which entails rotating the x-ray tube while simultaneously employing
multiple parallel detector arrays rather than a single detector row, has further
advanced spiral CT by reducing scan time and greatly increasing anatomic
coverage. Debilitated, elderly, or arthritic patients may require scanning in
the supine position; however, reformatted coronal images are usually easily
derived from the axially acquired data. With the widespread application of
spiral technology and filmless picture archiving and communications
systems (PACS), reformatted coronal and sagittal images may be obtained at
the workstation, obviating the need to scan the patient in multiple planes.
General surveys typically cover the base of the skull to the clavicles with 4
Management of Temporal Bone Malignancy
49
Radiological Diagnosis of Temporal Bone Malignancy
or 5 mm thick slices. The use of intravenous contrast is recommended. For
special regions of interest, patients may be scanned with additionally
acquired 2 mm slices and a higher zoom factor, or with newer scanners, the
same information can be obtained using reconstructed spiral data (Spreer et
al., 1995).
Multidetector CT
The current generation of 64-slice scanners allows for rapid
volumetric image acquisition with resolution in the range of 0.3 to 0.6 mm.
Because the data are acquired for an entire volume in a single pass, there is
no need for performing scans in multiple planes (axial, direct coronal, and
sagittal). The volumetric data can be reformatted rapidly in any desired
plane and without loss of resolution, which is a tremendous improvement
that allows visualization of the anatomy in novel ways. Another advantage is
that the current scanning protocols require approximately 5 to 10 seconds for
image acquisition. The incredibly rapid acquisition time greatly reduces
motion artifact and often the need for sedation in infants or young children,
which reduces not only the risk of the procedure but also the cost to the
health care system (Leblanc et al., 1999).
Figure 19: Sensation 64
scanner equipped with 32
detectors and two sources.
Images through the skull base
can be obtained in less than 10
seconds.
The
volumetric
acquisition
allows
for
reconstruction of the data in
any plane without loss of
resolution (Driscoll and
Lane 2007)
Management of Temporal Bone Malignancy
50
Radiological Diagnosis of Temporal Bone Malignancy
CT angiography
CT angiography can be performed on multidetector CT scanners as a
noninvasive means to obtain information concerning the skull base arterial
anatomy. The technique can be useful for identifying an aberrant carotid
artery or assessing vascular malformations or the interface between tumors
and arterial vasculature. Angiography should be performed in all cases in
which the carotid artery is at risk. When carotid resection is anticipated,
cerebral blood flow analysis should be used to determine resectability and
the need for revascularization. Consideration should also be given to
embolization when intraoperative hemorrhage is a concern. Contrast is given
during image acquisition and the image viewing software is used to subtract
out bone and other structures to allow isolated views of the arteries. The
high quality of these images often obviates the need for a formal angiogram
(Vrtiska et al., 2005)
There are important points considering each part in studying of the CT
of temporal bone.
External Ear
The entire external auditory canal can be seen on axial images at and
just below the level of the temporo–mandibular joint where it is S-shaped.
The tympanic membrane is stretching superiorly from the scutum down to
the tympanic annulus. The scutum is normally thin and sharply edged and is
an important bony landmark. The scutum, the tympanic membrane and the
tympanic annulus are best demonstrated on coronal images (Butler et al.,
1999).
Management of Temporal Bone Malignancy
51
Radiological Diagnosis of Temporal Bone Malignancy
Figure 20: Axial CT image at the level of
the
left
temporomandibular
joint
demonstrating the S-shape and the
junction of the cartilaginous and bony
portions of the external auditory canal.
1-External auditory canal (EAC),
2-cartilaginous portion of EAC,
3-bony portion of EAC, 4-pinna,
5- Tympanic membrane (Ahuja et al.,
2003).
Figure 21: Coronal CT image at the mid
bony portion of the left external auditory
canal. 1-Pars flaccida, 2-pars tensa,
3-tympanic membrane, 4-scutum,
5-tympanic annulus, 6-epitympanum,
7-mesotympanum, 8-hypotympanum,
9-tympanic segment of facial nerve
(Ahuja et al., 2003).
Middle Ear
The middle ear cavity is divided into three compartments in the
coronal plane. A line drawn from the lower edge of the scutum to the
tympanic portion of the facial nerve divides the superior compartment, the
epitympanum (attic), from the middle compartment, the mesotympanum
(tympanic cavity proper). A line drawn parallel to the floor of the external
auditory canal further divides the mesotympanum from the inferior
compartment, the hypotympanum. (Butler et al., 1999).
Management of Temporal Bone Malignancy
52
Radiological Diagnosis of Temporal Bone Malignancy
The epitympanum contains the head of the malleus, the malleo–
incudal articulation and the body and short process of the incus, which are
best demonstrated on axial images at about the level of the vestibule. The
roof of the epitympanum forms an important bony landmark, the tegmen
tympani. The tegmen serves as a barrier between the middle ear cavity and
the middle cranial fossa. The integrity of the tegmen tympani is best
evaluated on coronal images. The space situated between the scutum and
pars flaccida laterally and the neck of the malleus medially is known as the
Prussak’s space or the lateral epitympanic recess (Curtin et al., 1996;
Swartz et al., 1998).
Posteriorly the epitympanum opens into the mastoid antrum via the
aditus ad antrum; this opening is well demonstrated on both the axial and
coronal images. The medial wall of the epitympanum is the cortex overlying
the lateral semicircular canal. The tympanic portion of the facial nerve runs
posterolaterally inferior to the lateral semicircular canal. In this area the
bony floor of the facial nerve canal is very thin and may not be visualized on
coronal CT images. The tympanic segment of the facial nerve can also be
identified on the axial images running from the anterior genu
posterolaterally just below the lateral semicircular canal to the posterior
genu.
The mesotympanum contains the rest of the ossicular chain. On
coronal images the long process of incus is vertically oriented parallel to the
malleus manubrium, continuing as the rounded lenticular process with the
―hockey stick‖ appearance and with the facet to articulate with the head of
the stapes. The stapes hub and crura are best demonstrated on axial images
at the level of the oval window. The floor of the hypotympanum is a thin
Management of Temporal Bone Malignancy
53
Radiological Diagnosis of Temporal Bone Malignancy
plate of bone separating the middle ear cavity from the jugular bulb, and in a
case of dehiscence may allow a high-riding jugular bulb to herniate into the
hypotympanum (Swartz et al., 1998).
Inner Ear
The inner ear includes the membranous labyrinth within the bony
labyrinth (otic capsule). The membranous labyrinth contains endolymph and
is surrounded by perilymph, which together appear as low attenuation on CT
and high fluid signal on T2- weighted images but cannot be independently
demonstrated by imaging. The bony labyrinth consists of the cochlea, the
vestibule, the semicircular canals and the cochlear and vestibular aqueducts
(Leblanc et al., 1999).
There are three semicircular canals, namely the superior (anterior),
lateral (horizontal) and posterior semicircular canals. They are perpendicular
to each other. The plane of the posterior semicircular canal is parallel to the
petrous ridge while that of the superior semicircular canal is perpendicular to
it although both are in the vertical plane. The vestibule is separated from the
middle ear cavity by the oval window niche. The superior semicircular canal
forms a bony ridge at the roof of the petrous bone called the arcuate
eminence giving a landmark to the surgeon entering through the middle
cranial fossa (Swartz et al., 1998).
Management of Temporal Bone Malignancy
54
Radiological Diagnosis of Temporal Bone Malignancy
The following are consecutive axial CT images of the right middle and
inner ear from caudal to cephalic:
Figure 22: 1-Manubrium of malleus, 2-basal turn of cochlea, 3-cochlear aqueduct,
4-tensor tympani muscle, 5-tensor tympani tendon, 6-neck of malleus, 7-lenticular
process of incus, 8-incudostapedial articulation, 9-hub and posterior crus of stapes,
10-facial nerve, 11-pyramidal eminence, 12-sinus tympani, 13-bony margin inferior to
the oval window. PT—protympanum, MT— mesotympanum, PosT—posterior
tympanum (Ahuja et al., 2003).
Figure 23: 14-vertical portion of the basilar turn of cochlea, 15-apical turn of cochlea,
16-tympanic portion of the facial nerve canal, 17-head of malleus, 18-body of incus,
19-short process of incus, 20-lateral semicircular canal, 21-vestibule, 22-internal auditory
canal, 23-posterior semicircular canal, 24-vestibular aqueduct (Ahuja et al., 2003).
Management of Temporal Bone Malignancy
55
Radiological Diagnosis of Temporal Bone Malignancy
Figure 24: 25-malleoincudal articulation, 26-aditus ad antrum, 27-anterior genu of the
facial nerve, 28-labyrinthine portion of the facial nerve canal, 29-superior semicircular
canal (Ahuja et al., 2003)..
In general, high resolution CT scan gives good accuracy in
determining the presence of the tumor and its extensions regarding the
presence of
bone invasion or not. However distinguishing mucosal
thickening from tumor on CT imaging was more difficult. MRI scans were
more sensitive in this respect (Driscoll and Lane 2007).
High resolution CT scan is rapidly becoming the procedure of choice
for evaluation of temporal bone, nasopharynx, infratemporal fossa and base
of skull. Making it ideally suited for evaluation of primary tumors of the ear
which can involve any of these areas. Intravenous contrast material is
helpful in identifying tumor extension beyond the confines of the temporal
bone especially in the parotid gland, infratemporal, fossa and dura of the
middle or the posterior cranial fossa (Shaffer et al., 1980).
So, CT is helpful in the staging, management and prognosis of
temporal bone malignancies (Goodwin and Jesse, 1980).
Management of Temporal Bone Malignancy
56
Radiological Diagnosis of Temporal Bone Malignancy
In the following, shows the usage of CT in diagnosing temporal bone
lesions:
Figure 25: Oblique coronal CT
scan shows an extensive
destructive lesion of the left
temporal bone with mottled
calcification (Takahashia,
2002).
Figure 26: An endolymphatic
sac tumor in a 15-year-old
patient with Von HippelLindau disease who first
developed facial paralysis
1year before presentation,
severe vertigo and sudden
sensorineural deafness on the
right side. CT scan reveals the
tumor extending superiorly
with destruction of the right
lateral
and
superior
semicircular
canals.
No
evidence
of
contralateral
endolymphatic
sac
tumor
(Megerian
2007).
Management of Temporal Bone Malignancy
&
Semaan,
57
Radiological Diagnosis of Temporal Bone Malignancy
Magnetic Resonance Imaging (MRI) of The Temporal
Bone
MRI has been the most important development in the assessment of
skull base lesions. The examination is performed in the axial, coronal, and
sagittal planes with 3-mm sections. All signal intensities (T1- and T2weighted, and proton density images) are applied for evaluation of the
anatomy (T1-weighted images) and lesion characterization (T2-weighted
images). Also MRI is important in defining intracranial tumor extension and
differentiation of cystic from solid lesions. Magnetic resonance angiography
(MRA) defines the vascular anatomy in relation to tumors and cysts and may
also depict hypervascularity of lesions (Driscoll and Lane 2007).
Soft tissue discrimination is best achieved with MRI. Tumor can
usually be separated from muscle and fat using T1- weighted images, proton
density images and T2-weighted images. If tumor invades fatty planes, the
normal high signal intensity of these planes is obliterated by the more
intermediate signal intensity of the tumor. This is relevant to the evaluation
of the pterygoid fossa, parapharyngeal space at the base of skull and exit
foramina of the cranial nerves (foramen rotundum, ovale, spinosum, and
stylomastoid foramen), which all contain fatty tissue. Perineural tumor
spread will obliterate the fat at the extra cranial opening of the foramina
(Curtin et al., 1985).
With the introduction of gadolinium, lesion detection and conspicuity
have been increased. Recently, fat suppression techniques with contrast
enhancement have been used to define tumor extent optimally in the region
below the skull base (Laine et al., 1990; Tien, 1992).
Management of Temporal Bone Malignancy
58
Radiological Diagnosis of Temporal Bone Malignancy
Magnet strength in MRI
Currently, the most widely available magnet strength is 1.5 T, with
many institutions having one or more 3-T magnets. Higher strength magnets
offer several potential advantages, including improved resolution, increased
signal-to-noise ratio, and faster scanning times. Higher strength magnets also
can create more problems with certain artifacts, so a stronger magnet does
not always yield better images. Higher strength magnets also have the
potential to cause tissue injury caused by heating (Driscoll and Lane, 2007).
Figure 27: An MRI scanner. Large patients and patients with claustrophobia may not be
able to be accommodated or tolerate the narrow bore of high-strength MRI scanner
(Driscoll and Lane, 2007).
Management of Temporal Bone Malignancy
59
Radiological Diagnosis of Temporal Bone Malignancy
Here are MRI images demonstrating lesions that could affect the
temporal bone:
Figure 28: Magnetic resonance imaging of the internal acoustic canal revealed the
following characteristics: The lesion originated from the petrous part of the left temporal
bone, obliterated the pontomedullar and pontocerebellar cistern, pressed the brainstem
and left cerebellar hemisphere but did not cause apparent effects of deviation, entered
below the temporal lobe, was sometimes cystic and lobulated, demonstrated homogenous
postgadolinium contrast, occupied the entire mastoid and middle ear, narrowed the
external ear canal from the upper side, and disturbed the cortex integrity in a 2 cm by 3
cm field at the mastoid cortex superior section. The mass extended to the left jugular
foramen. There was a signal void loss that could have been associated with the absence of
flow in the left internal jugular vein (Yilmaz et al., 2008).
Management of Temporal Bone Malignancy
60
Radiological Diagnosis of Temporal Bone Malignancy
Figure 29: Rhabdomyosarcoma in a 6-year-old girl presenting with deafness on the right
side and sudden onset of facial paralysis.
(A) Unenhanced spin echo (SE) T1-weighted image. The hypointense fluid signal in the
IAC on the right side is replaced by soft tissues with an isointensity to brain tissue
(arrowheads). The fat signal in the petrous apex on the right side is replaced by soft
tissues (large arrow). Compare with the normal fatty marrow signal in the left petrous
apex. There seems to be extension in the anterior side of the petrous bone, probably along
the course of the facial nerve (small arrows). The middle ear signal void is replaced by an
isointense signal
(B) Postgadolinium SE T1-weighted image. There is strong enhancement of the mass
lesion in the IAC and cerebellopontine angle (arrowheads). There is also enhancement of
the mass lesion in the petrous apex (large arrow) and in the anterior part of the petrous
bone, probably in the extension along the facial nerve (small arrows). Although the lesion
mimics a facial nerve schwannoma, these lesions are considered extremely rare in young
children. A middle and inner ear mass lesion in a child should always include
rhabdomyosarcoma in the differential diagnosis (De Foer et al., 2009).
Management of Temporal Bone Malignancy
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Radiological Diagnosis of Temporal Bone Malignancy
Figure 30: Adenoid cystic carcinoma with perineural spread along the facial nerve in a
35-year-old woman with persistent and painful facial nerve palsy lasting for at least 6
months. (A) Axial T2-weighted MR imaging at the level of the parotid gland shows a
slightly hyperintense, heterogeneous, unsharp mass lesion in the left parotid gland
(arrows): adenoid cystic carcinoma of the left parotid gland. (B) Axial unenhanced T1weighted MR imaging at the level of the stylomastoid foramen. The right stylomastoid
foramen demonstrates normal hyperintense signal attributable to the fat around the facial
nerve (large arrow). This fatty signal on the left side has disappeared because of tumoral
infiltration along the facial nerve (small arrow) (De Foer et al., 2009).
Management of Temporal Bone Malignancy
62
Radiological Diagnosis of Temporal Bone Malignancy
Registration and Fusion of CT and MRI of the Temporal
Bone
CT and MRI of the temporal bone provide complementary
information about temporal bone structures and pathologies. CT allows
imaging of bony structures, whereas MRI enables imaging of soft tissue
structures. So image registration and fusion gains a significant improvement
over conventional images in depicting the relationship between bone and
soft tissue (Panigrahy et al., 2000).
An accurate image registration and fusion could be especially useful
in the temporal bone, because here, small soft tissue structures are embedded
in the surrounding bone. For example, to assess the facial nerve along its
entire course, one has to switch from the direct MR imaging of the nerve in
the internal auditory canal (IAC) to the indirect CT imaging of its bony
canal, aligning the images mentally for this transition. The same problem
occurs when other structures such as the inner ear and IAC and their bony
delineation need to be aligned (Hill et al., 1994).
So, in the registered images, the facial nerve can be seamlessly
followed along its entire course. In malformations, this could improve
diagnostic accuracy, because the facial nerve and its canal can be identified
more reliably. For tumor surgery within the IAC, accurate surgical planning
is necessary. Almost all important surgical landmarks such as the IAC, facial
nerve canal, inner ear, vestibular and cochlea aqueduct are all solely
displayed in CT and the tumors are mostly solely displayed in MRI. Without
registration, the surgeon relies on a rough assessment of the surgical
approach by mentally integrating the information of both modalities.
Management of Temporal Bone Malignancy
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Radiological Diagnosis of Temporal Bone Malignancy
Registration of CT and MRI allows an assessment of the tumor extent
relative to important surgical landmarks that need to be avoided during
surgery. Especially the 3D imaging of the tumor together with important
surgical landmarks can be beneficial for surgical planning and guiding
during surgery. This method allows measurements to be taken within the
registered data set to objectively assess whether it is possible to reach the
tumor through certain surgical approaches and therefore to assess the
feasibility of various surgical approaches (Hans et al., 1999).
So co-registration and subsequent 3 dimensional visualization were
evaluated for high-resolution CT and MRI of the temporal bone. Coregistration resulted in highly accurate and feasible multimodality images.
We found that registered images are superior to conventional images for
delineating the relationship between bony and soft tissue structures of the
temporal bone. Excellent applications are the surgical planning for cochlea
implantation and tumor surgery of the IAC, which can be further improved
by 3D imaging of the structures from either modality together in 1 model.
The only trade-off is the time need for the post processing; therefore, it is
preferable to do the registration and fusion of the temporal bone in special
cases (Ellul et al., 2000).
Management of Temporal Bone Malignancy
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Radiological Diagnosis of Temporal Bone Malignancy
Figure 31: Registration and Fusion of CT and MRI of the Temporal Bone
(A) Lesion is present in the right internal auditory canal (arrow) in registered and
fused CT and MRI of the temporal bone.
(B) For surgical planning, the MRI-given tumor (yellow) and critical CT-given
surgical landmarks such as the labyrinth (blue) and the facial nerve canal (gray)
(C) As well as the bony skull base (white) can be displayed together (Bartling et
al., 2005).
Management of Temporal Bone Malignancy
65
Surgical Management
of
Temporal Bone Malignancy
Surgical Management of Temporal Bone Malignancy
Cancer of the temporal bone is a challenging disease to be treated
effectively. Modern management of this disease consists of combined
modality therapy, including surgery to remove all evident disease and
radiation therapy to treat the margins of resection. The surgical procedure of
choice depends on the extent of disease and consists of lateral resection of
the temporal bone; subtotal resection of the temporal bone; subtotal
resection of the temporal bone with extension to the infratemporal fossa,
jugular foramen, or dura; and total resection of the temporal bone, which
includes removal of the petrous apex (Hirsch et al., 2008).
The management of cancer of the temporal bone was first discussed
by Politzer in 1883. Radical mastoidectomy with radiation therapy was
previously the recommended treatment, but cure rates were quite low. In
1954, Parsons and Lewis described the technique of en bloc subtotal
temporal bone resection. Lederman presented the first large series of
patients treated by radiation therapy in 1965 and established the concept of
combined therapy at a time when the role of radiation in treating cancer of
the temporal bone was not yet well accepted. In 1984, Graham and
colleagues reported total en bloc resection of the temporal bone, including
the internal carotid artery.
Postoperative radiation therapy should encompass the resection
margins, residual parotid gland, infratemporal fossa and ipsilateral neck
(John et al., 2002)
Management of Temporal Bone Malignancy
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Surgical Management of Temporal Bone Malignancy
Figure 32: Types of temporal bone resections
Axial (A) and coronal (B) illustrations demonstrating (1) lateral resection of the temporal
bone, (2) subtotal resection of the temporal bone, and (3) total resection of the temporal
bone. The carotid artery is preserved in this illustration (Hirsch et al., 2008).
Management of Temporal Bone Malignancy
67
Surgical Management of Temporal Bone Malignancy
Depending on the stage of disease, surgical treatment of cancer arising
in the temporal bone is potentially a major undertaking. The risk of
morbidity and mortality increases with factors such as advanced age and
medical conditions as coronary artery disease, pulmonary disease, diabetes
mellitus, and peripheral vascular disease. However, because combined
modality therapy that includes major surgery appears to be the only
treatment that offers any reasonable chance of control of cancer, there is no
absolute medical contraindication to surgical treatment (De Vries et al.,
1990).
The treatment program depends primarily on the extent of the cancer.
Cancer limited to the EAC (T1, T2) is treated by lateral temporal bone
resection with superficial parotidectomy and preservation of the facial nerve.
Rarely, the cancer may be small, isolated in the lateral cartilaginous aspect
of the EAC, and not eroding bone, thereby permitting sleeve resection of the
external canal skin, lateral to the tympanic membrane. In practice, sleeve
resection is probably not oncologically adequate (Moffat et al., 2005).
Cancer that has invaded the middle ear and mastoid cavities (T3) is
treated by subtotal temporal bone resection. Total temporal bone resection
(sometimes called radical temporal bone resection) is performed when
cancer
extends
to
the
petrous
apex.
Cancer
extending
to
the
temporomandibular joint, neck, dura, or infratemporal fossa (T4) will
require resection of these structures (Moffat et al., 2005).
Parotidectomy is routinely performed in conjunction with temporal
bone resection. Ideally, the parotid is resected en bloc with the temporal
bone. However, for T1 and T2 cancers, superficial parotidectomy is
Management of Temporal Bone Malignancy
68
Surgical Management of Temporal Bone Malignancy
sufficient. For T3 and T4 cancers and if the facial nerve must be resected,
total parotidectomy is performed (Hirsch et al., 2008).
Supraomohyoid neck dissection is performed in most cases. The
lymphatic drainage of pinna and EAC lesions is not entirely predictable but
will often extend to the upper jugular nodal chain. Also, exposure of cervical
structures provides safe control of the great vessels, if needed. In a clinically
N0 neck, neck dissection can be done as a staging procedure to assist in the
decision as whether to proceed with postoperative radiation therapy. The
survival benefit provided by elective neck dissection is unclear (Moffat et
al., 2005).
Neck dissection is commonly carried out at the time of temporal bone
resection, which provides good local/regional control but does not seem to
affect survival (Moody et al., 2000).
The presence of metastatic cancer, especially in the neck, should be
detected before therapy. Metastasis to the neck is unusual in cancer of the
temporal bone, but a thorough physical examination and CT or MRI with
contrast enhancement should detect lymph node involvement. Spread of
cancer to the lymph nodes in the superficial lobe of the parotid gland is more
common, so the superficial lobe of the parotid gland is usually removed
during surgery with preservation of the facial nerve. If the pathology is
squamous cell carcinoma, a metastatic evaluation consisting of chest
radiography and liver function testing is adequate. In malignant tumors with
a high predilection for systemic spread such as melanoma, CT scanning of
the chest, abdomen, and pelvis, as well as whole-body bone scanning, should
be performed (Myers et al., 2008) .
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Surgical Management of Temporal Bone Malignancy
Preoperative staging determines the scope of the planned procedure
and the necessity for a team approach. Neurosurgical participation is
appropriate when surgery requires intracranial resection. Similarly, wound
closure after tumor removal may necessitate transfer of regional or distant
tissue, thus warranting consultation with a reconstructive surgeon. Surgical
treatment of cancer of the temporal bone usually requires a long duration of
anesthesia and can entail major blood loss and fluid shifts, intracranial
manipulation, and postoperative stress, including fluid and electrolyte
abnormalities, pulmonary and cardiac stress, coagulation abnormalities, and
the possibility of aspiration. The patient's medical status should be optimized
before surgery (Hirsch et al., 2008).
Incisions vary according to the extent of the tumor. The incision is
designed postauricular and either to incorporate the pinna in case when it
must be removed or to retract it anteriorly, or superiorly. Then the incision is
extended superiorly into the temporal fossa and inferiorly into the neck.
When tumor invasion of the conchal cartilage or periauricular skin is
suspected, an appropriate skin island is incorporated into the overall design.
A blind-sac closure of the EAC helps contain the specimen. The EAC skin is
sutured shut to avoid tumor spillage. The outline of the incisions should
preserve the blood supply to the remaining auricle. The anterior and
posterior skin flaps are elevated. The superficial temporal fat pad is elevated
with the anterior skin flap in a subperiosteal plane over the zygomatic arch
(Neely, 1982).
Management of Temporal Bone Malignancy
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Surgical Management of Temporal Bone Malignancy
Lateral temporal bone resection
According to the extent of the disease, lateral temporal bone resection
can be classified into four types. Type I resection consists of removal of
tympanic bone & EAC lateral to the tympanic membrane. The type II
resection consists of the removal of the entire tympanic bone, the tympanic
membrane, the incus and the malleus preserving the facial nerve and the
inner ear. Type III resections remove, in addition to type II, the distal facial
nerve and fallopian canal, the mastoid tip, the styloid process, and the
stylomastoid foramen. The type IV resection consists of the removal of only
the mastoid tip and the inferior portion of the tympanic bone. The decision
to perform a lateral temporal bone resection and the decision as to what type
of temporal bone resection to perform is based on the location and extent of
the tumor (Medina et al., 1990).
A lateral temporal bone resection is considered when a malignant
tumor clinically and /or radiographically involves the postauricular sulcus
skin, the concha, and the external auditory canal or invading the tympanic
bone the mastoid cortex or both but doesn’t invade the middle ear or any
pneumatized space in the temporal bone (Medina et al., 1990).
After the incision cortical mastoidectomy and exploration of the
middle ear is done through an extended facial recess approach any suspected
tissues should be removed and must be examined by frozen section. Then
the bone lateral to the epitympanum is removed to the level of root of
zygoma and temporomandibular joint. The bone lateral to hypotympanum
and the facial nerve is also removed in an anterior direction to the
temporomandibular joint (Medina et al., 1990).
Management of Temporal Bone Malignancy
71
Surgical Management of Temporal Bone Malignancy
Then after that we can perform one of the following types of lateral
temporal bone resections that can be selected according to the location and
extent of the tumor:
Type I lateral temporal bone resection (sleeve resection of the EAC)
is considered when the tumor originated in the concha or in the periauricular
skin but didn’t involve the skin of the EAC grossly, didn’t infiltrate into the
parotid, the temporomandibular joint or involved the facial nerve. The
tympanic bone is cut circumferentially in a plane lateral to the tympanic
membrane the complete circumference of the EAC is cut with a drill into the
temporomandibular joint. Frozen section from the entire circumference of
medial margin of skin of the EAC and from the capsule of the
temporomandibular joint is taken. If proved positive for tumor invasion
consider type II lateral temporal bone resection (Medina et al., 1990).
Figure 33: lateral temporal bone resection type I. Left, outline of the bone cuts in the
EAC. Center, EAC fractured forward (the bone cut is performed just lateral to the
tympanic membrane and the facial nerve. Right, remaining structures and defect after
removal of the surgical specimen.
Type II lateral temporal bone resection this operation is performed
when the tumor is originated from the EAC or extended grossly into it from
Management of Temporal Bone Malignancy
72
Surgical Management of Temporal Bone Malignancy
the pinna or the periauricular skin. After the initial steps described
previously were completed, the facial recess is opened, the incus will be
disarticulated from the stapes, and the tensor tympani tendon is cut. The
fallopian canal is identified, but not opened, from the geniculate ganglion to
the stylomastoid foramen, the chorda tympani is cut. The bone about the
hypotympanum is removed in a plane medial to the tympanic annulus and
just lateral to the jugular foramen and the carotid canal. The removal of the
bone is carried up to the glenoid fossa. After completion of this step of the
operation, the lateral portion of the temporal bone to be resected was only
connected to the rest of the temporal bone by a thin plate of bone between
the hypotympanum of the middle ear and the glenoid fossa in the area of the
eustachian tube. This will be easily fractured forward by gentle pressure on
the bony canal, freeing the surgical specimen (Medina et al., 1990).
Figure 34: lateral temporal bone resection type II. Left, outline of the bone cuts in the
tympanic bone and potential extension to the neck of the condyle. Center, the tympanic
bone with attached tympanic membrane, malleus, and incus has been fractured forward.
Right, remaining structures and defect after removal of the surgical specimen.
Type III lateral temporal bone resection when the location and extent
of the tumor dictated the need to resect the entire tympanic bone, the
stylomastoid foramen, and the facial nerve, as in the case of persistent or
Management of Temporal Bone Malignancy
73
Surgical Management of Temporal Bone Malignancy
recurrent tumors following superficial parotidectomy the bone cuts are
performed in a plane medial to the fallopian canal, the stylomastoid foramen,
and styloid process, which will be included in the resected specimen. The
jugular foramen and the internal carotid artery are the medial limit of the
resection (Medina et al., 1990).
Figure 35: lateral temporal bone resection type III. Left, outline of the bone cuts the
fallopian canal and potential extension to the neck of the condyle. Center, lateral portion
of the temporal bone to be resected, including the styloid process, fallopian canal,and
facial nerve. Right, remaining structures and surgical defect.
Type IV lateral temporal bone resection this type of resection is done
when the tumor is adjacent only to the mastoid tip, the inferior aspect of the
tympanic bone, or both. The EAC lumen, the tympanic membrane, and the
middle ear structures are preserved while the inferior portion of the tympanic
bone and the mastoid tip is resected. Depending upon the clinical situation,
the facial nerve and the styloid process could be resected or preserved
(Medina et al., 1990).
Management of Temporal Bone Malignancy
74
Surgical Management of Temporal Bone Malignancy
Figure 36: lateral temporal bone resection type IV. Left, outline of the bone cuts through
the mastoid tip and inferior portion of the tympanic bone. Center, resected portion of the
temporal bone displaced forward. Right, remaining structures and surgical defect.
The resection of the lateral portion of the temporal bone could be done
in conjunction with a parotidectomy, a partial mandibulectomy or resection
of the glenoid fossa and the floor of the middle cranial fossa, depending
upon the extent of the tumor (Hirsch et al., 2008).
The resulting surgical defect is repaired with a temporalis muscle flap,
a split thickness skin graft, or both, whenever possible. Large defects,
particularly those in which the dura or the internal carotid artery was
exposed, will be repaired with myocutaneous flaps (Medina et al., 1990).
The four types of lateral temporal bone resections described here can
be used for the surgical treatment of selected malignant tumors of the ear,
periauricular skin, and the parotid. Proper use of these techniques requires a
methodical preoperative evaluation and a systematic intraoperative
assessment of the extent of the tumor. In general the morbidity associated
with the lateral temporal bone resections is low (Medina et al., 1990).
Management of Temporal Bone Malignancy
75
Surgical Management of Temporal Bone Malignancy
Subtotal Temporal bone resection
It is indicated in the case of cancer extending medial to the tympanic
membrane and invading the middle ear, hypotympanum, otic capsule, facial
nerve, or mastoid (Kinney, 1989).
The approach for lateral resection of the temporal bone is performed
as described previously, with examination of the middle ear through the
facial recess and mastoid cavity for cancer. If the cancer is present and the
decision is to be subtotal resection we proceed as follows.
The temporalis muscle is elevated in a subperiosteal fashion and
reflected inferiorly. It must be separated from the lateral pterygoid muscle,
and care should be taken not to injure the deep temporal arteries supplying
blood to the temporalis muscle (Prasad and Janecka, 2010).
A temporal craniotomy is performed, and the intracranial portion of
the middle meningeal vessels is coagulated. This maneuver will define an
intracranial margin to establish resectability of the tumor mass. If the tumor
extends through dura, the dura can be resected free of the temporal lobe.
However, extension of the tumor into the temporal lobe makes it inoperable
(Sataloff et al., 1988).
The facial nerve can be handled differently, depending on tumor
invasion of the parotid gland. When the parotid gland is involved, peripheral
branches of the facial nerve are identified and then divided. The entire
parotid gland is dissected and mobilized posteriorly, while the attachment to
the EAC is maintained. When the parotid gland is suspected to be free of
tumor, the facial nerve trunk is located in the usual manner at the
Management of Temporal Bone Malignancy
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Surgical Management of Temporal Bone Malignancy
tympanomastoid suture and divided. The parotid gland, along with the distal
stump of the facial nerve, is dissected free of the EAC and mobilized
anteriorly. The ninth cranial nerve, the greater auricular nerve, or cervical
cutaneous nerves can be used as cable grafts for facial nerve reconstruction
(Hirsch et al., 2008).
The jugulodigastric region is explored, and cervical lymph nodes are
sent for frozen section pathologic analysis. Regional metastases determine
the need for a formal cervical lymphadenectomy (Prasad and Janecka,
2010).
Cranial Nerves IX, X, XI, and XII; the internal jugular vein; the
external and internal carotid arteries are dissected. The sternocleidomastoid
and digastric muscles are detached from their attachment to the mastoid. The
masseter is detached from the zygomatic arch, allowing exposure of the
zygoma and mandible. Zygomatic and mandibular osteotomies can then be
performed (Prasad and Janecka, 2010).
The meniscus of the temporomandibular joint is separated from the
glenoid fossa. The stylomandibular and sphenomandibular ligaments are
divided and allow removal of the mandibular segment (Prasad and Janecka,
2010).
The lateral and medial pterygoid muscles are resected either en bloc
with the specimen or separately, depending on tumor invasion. In a
subperiosteal manner, the contents of the infratemporal fossa are elevated off
the floor of the middle fossa to expose the middle meningeal artery and vein
in the foramen spinosum and the mandibular division of the trigeminal nerve
in the foramen ovale. The contents of the foramen spinosum are bipolarly
Management of Temporal Bone Malignancy
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Surgical Management of Temporal Bone Malignancy
coagulated and divided. Frequently, the venous plexus of the foramen ovale
requires bipolar coagulation and packing with oxidized cellulose. The
cartilaginous eustachian tube is divided, and the anterior end is sutured
closed to prevent postoperative cerebrospinal fluid rhinorrhea (Chung and
Pensak, 2005).
Management of Temporal Bone Malignancy
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Surgical Management of Temporal Bone Malignancy
Figure 37: A: Incisions vary according to whether the tumor is contained in the temporal
bone. B: The facial nerve can be divided peripherally at the distal branches or centrally at
the facial nerve trunk, depending on involvement of the parotid gland. C: After
osteotomies and removal of the zygomatic arch and mandibular segments, dissection in
the infratemporal fossa continues (Prasad and Janecka 2010).
Management of Temporal Bone Malignancy
79
Surgical Management of Temporal Bone Malignancy
A mastoidectomy is then performed, which skeletonizes the sigmoid
sinus and the jugular bulb. Continuing anteriorly, the carotid artery is
exposed in its vertical and horizontal petrous segments and may be
mobilized anteriorly (Chung and Pensak, 2005).
From a subtemporal or middle fossa exposure, the internal auditory
canal is identified and opened with cranial nerves VII and VIII divided. Any
remaining bony connections are freed. The lines of resection are through the
carotid canal at the lateral aspect of the IAC, through the cochlea and the
exiting jugular foramen (Chung and Pensak, 2005).
The middle and posterior fossa dura is inspected for carcinomatous
involvement. Any involved areas are resected, and margins are sent for
frozen section pathologic examination. The temporal lobe and cerebellum
are also examined, and limited involvement of the inferior temporal gyrus
and cerebellum can be resected. When intradural hemostasis is achieved, the
dura is closed in a watertight manner using pericranium or fascia lata
(Hirsch et al., 2008).
Total Temporal Bone Resection
Total en bloc resection of the temporal bone with clear margins
could be the procedure needed for oncologic control. It includes resection of
the petrous apex with the main temporal bone specimen (Sataloff et al.,
1988).
The vital structures that surround the temporal bone demand that a
meticulously controlled approach be performed to avoid catastrophic
vascular and neurologic consequences. Even if the carotid artery is to be
Management of Temporal Bone Malignancy
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Surgical Management of Temporal Bone Malignancy
sacrificed with the specimen, proximal and distal control must be achieved.
Similarly, the brain, dura, and cranial nerves must be dissected and isolated.
Although a “no–touch” tumor approach remains the technique to which we
aspire, it is often not accomplished to safely obtain access to the petrous
portion of the temporal bone (Sataloff et al., 1988).
Figure 38: (A) Incision marked out for extended temporal bone excision. (B) First step is
to place colored slings around the great vessels in order to ensure vascular control and
identify cranial nerves IX, X, XI, and XII prior to completing the supra-omohyoid neck
dissection. (C) Wide access and good visualization of the jugular and carotid foramina
and skull base is essential before completing the en bloc extended temporal bone
excision. (D) View of the large defect on completion of the resection (Moffat, 2009).
After completion of subtotal temporal bone dissection, proximal
control of the ICA is obtained either at the skull base or in the neck. Distal
control is achieved in the floor of the middle cranial fossa via middle fossa
craniotomy. The carotid artery is exposed so that a clip can be placed on it
Management of Temporal Bone Malignancy
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Surgical Management of Temporal Bone Malignancy
for distal control if necessary. The bone lateral to the ICA at the genu is
removed, and the ICA is dissected free from its canal from the skull base to
the foramen ovale (Prasad and Janecka 2010).
A thick, fibrous ring of tissue surrounds the ICA at the carotid
foramen. When mobilizing this portion of the ICA, it is safer to first dissect
circumferentially around the fibrous tissue rather than along the carotid itself
because the risk of carotid laceration is high. The fibrous ring can be left
intact while the ICA is mobilized. Once adequate exposure has been
achieved, the remainder of the otic capsule containing the cochlea is drilled
(Prasad and Janecka 2010).
Anteriorly, the petrous apex is drilled to complete total resection of
the temporal bone. The eustachian tube lays inferolateral to the carotid canal
at the genu and travels anteromedially. The eustachian tube can be resected
anteriorly to the level of the foramen ovale. If cancer is found anterior to this
area, nasopharyngeal resection and possibly cavernous sinus dissection will
be necessary to achieve total resection. The transected end of the eustachian
tube is sutured closed to prevent CSF rhinorrhea (Sataloff et al., 1988).
Reconstruction after temporal bone surgery
The goals of soft tissue reconstruction after temporal bone resection
include alleviation of cosmetic deformity, prevention of CSF leak, and
promotion of adequate healing (Hirsch et al., 2008).
In most cases, these objectives are best accomplished with a
vascularized flap. To prevent communication between the nasopharynx and
the middle ear space after lateral temporal bone resection, the eustachian
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Surgical Management of Temporal Bone Malignancy
tube is obliterated by scarifying the mucosa and filling the lumen with bone
dust, Surgicel, or a plug of muscle (Hirsch et al., 2008).
The resultant defect after lateral resection of the temporal bone is
similar to that after radical mastoidectomy, and there is usually little risk of
cerebrospinal fluid (CSF) leak, so adequate tissue coverage can be
accomplished with a split–thickness skin graft. However, because most
patients require radiation therapy after surgery or have previously undergone
radiation therapy, so a vascularized flap to promote healing provides the
optimal result. The posterior one half of the temporalis muscle is separated
from the anterior portion, and while pedicled inferiorly, the posterior portion
of the muscle is rotated into the mastoid cavity (Hirsch et al., 2008).
The surgical defect after subtotal temporal bone resection extends
medially through the otic capsule and poses a greater likelihood of a CSF
leak. If infratemporal fossa dissection has not been performed, the resultant
defect is not significantly larger than one resulting from lateral temporal
bone resection. Usually, a pedicled posterior temporalis flap provides
adequate coverage. Other options include a lower island trapezius or
pectoralis major myocutaneous flap. If these flaps cannot be mobilized
superiorly to cover the temporal bone defect adequately, a free flap with
microvascular anastomosis to the superficial temporal or facial artery system
can be used. The most commonly used free flap is the rectus abdominis,
although a scapular or latissimus dorsi free flap can also be used. The
temporomandibular joint is not reconstructed routinely (Hirsch et al., 2008).
If the facial nerve has been resected and there is an adequate proximal
stump, it is reconstituted with a cable nerve graft. More commonly the sural
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Surgical Management of Temporal Bone Malignancy
nerve is used. The greater auricular nerve can be used if the length required
is less than 6 cm. Otherwise, a sural nerve graft is necessary to obtain a
longer donor graft for anastomosis between the proximal and distal ends of
the facial nerve. If facial nerve resection has been performed distal to the pes
anserinus, both the upper and lower branches are reconstructed. If the
proximal stump of the facial nerve has been resected at the brain stem with
an inadequate length left for anastomosis, a hypoglossal-to-facial (XII to
VII) nerve anastomosis can be performed. If a CSF leak is a potential
problem, the wound should be closed in at least three layers (Hirsch et al.,
2008).
Complications of temporal bone resection
Aggressive temporal bone resection may be associated with major
intracranial complications. Extensive brain retraction can result in lower
cranial nerve palsy, cerebellar or temporal lobe edema and dysfunction, and
cerebral
infarction.
Major
arterial
injuries
can
cause
disastrous
consequences, and all precautions should be taken to prevent these injuries.
As in the case of dissection of the ICA can result in injury with bleeding and
stroke (Ariyan et al., 1981).
So intraoperatively, before manipulation of ICA, proximal control of
the vessel in the neck or at the skull base and distal control in the horizontal
portion of the intrapetrous carotid artery should be obtained. In this way, if
an injury to the ICA occurs, rapid control of the situation can be achieved. If
a laceration of the ICA occurs, it is managed by either primary repair, repair
with a patch, bypass grafting using the saphenous vein, or sacrifice of the
ICA without reconstruction. Venous complications are also possible after
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Surgical Management of Temporal Bone Malignancy
temporal bone resection, especially if manipulation or resection of the
sigmoid sinus is performed (Ariyan et al., 1981).
Another complication is CSF leak. The main morbidity of a CSF leak
is increased risk for the development of meningitis. Because meningitis can
be a life–threatening condition, prevention plus control of CSF leaks is very
important. CSF leaks occur when there is inadequate closure of the dura in
conjunction with a path for egress of CSF through the soft tissues to the
external environment. The usual sites of leakage are the eustachian tube,
incision site, and remnant of the EAC. Prevention is the most efficacious
method of management. All dural closures should be made as watertight as
possible. Any potential dead spaces should be obliterated by placement of
muscular flaps or autologous fat grafts. The final barriers to CSF flow, skin
closure and the eustachian tube, should be closed or obliterated in watertight
fashion. A drain is not placed in the wound. Postoperatively, the patient's
head is kept elevated and the patient is instructed to avoid straining or
performing a Valsalva maneuver. A pressure dressing is maintained for 5
days (Skedros et al., 1993).
Wound infections occur infrequently after resection of the temporal
bone. Appropriate treatment is no different from treatment elsewhere in the
head and neck (Hirsch et al., 2008).
One of the most rapidly progressive and potentially fatal
complications is acute intracranial hemorrhage, which if not treated
promptly can lead to irreversible cerebral injury with uncontrolled cerebral
edema or brain stem herniation and even death (Hirsch et al., 2008).
Management of Temporal Bone Malignancy
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Radiotherapy and
Stereotactic Radiosurgery
in
Temporal Bone Malignancy
Radiotherapy and Stereotactic Radiosurgery in Temporal Bone Malignancy
Radiotherapy alone has been used to treat ear carcinoma in large
radiotherapy centers. Lederman and others showed that in 1965 the overall
5-year survival rate was 24% in patients treated for external canal carcinoma
by radiotherapy alone. Arthur reported that radiotherapy alone can achieve
an overall 5-year survival rate of 42%. In 1987, Million and Cassisi reported
an 80% two year survival rate for patients treated by radiotherapy alone. In
1989, Golding-Wood and others suggested that radiotherapy was the
preferred initial treatment in almost all patients (Shiratoa et al., 2000).
However, with the development of en bloc resection and plastic
surgery, radiotherapy has shifted from being an initial treatment to being an
adjunct to surgery in many institutions. In these institutions, the use of
radiotherapy alone is reserved as a treatment for inoperable advanced
disease, and therefore the survival rate following radiotherapy alone is
reported to be very low. Some authors have suggested that conservative
surgery combined with definitive radiotherapy is as effective as or more
effective than aggressive surgery (Testa et al., 1997).
In spite of intraoperative monitoring of margins of resection, many
cases showed tumor invasion beyond surgical margins following nerves,
vessels, and fasciae. Because incomplete surgical excision is the major
reason for treatment failure, postoperative radiotherapy has become an
important measure to achieve local control of the disease (Graham et al.,
1984).
Adenoid cystic carcinomas are a special entity in tumors of the ear,
showing a slow proliferation rate and a low tendency of lymphatic spread.
However, when excised incompletely, lesions recur locally and the
Management of Temporal Bone Malignancy
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Radiotherapy and Stereotactic Radiosurgery in Temporal Bone Malignancy
prognosis is poor. So a “wait and see” policy without postoperative
radiotherapy could only be used in completely en bloc resected patients with
adenoid cystic carcinoma. (Perzin et al., 1982).
General management in external auditory canal malignancy
Tumors of the external ear are most often treated with limited surgery
or external radiation therapy. Treatment in early stages with irradiation is
usually in the form of electron beam therapy. Surgery is beneficial if the
lesion has invaded the cartilage of the ear or extends medially into the
middle ear. Advanced lesions involving a significant portion of the ear canal
are managed with a combination of irradiation and surgery (Shockley and
Stucker 1987).
Treatment of draining lymphatics is normally not required for early
stages of external ear tumors. Lesions over 4 cm and those with cartilage
invasion have an increased risk of nodal spread; so prophylactic neck
dissection is recommended. Most investigators do not agree with this
approach because the overall chance of lymph node involvement in tumors
of the external ear is only 16% (Shiratoa et al., 2000).
Interstitial irradiation using after loading
192
Ir, particularly for tumors
smaller than 4 cm, is also an effective method of treatment, affording
excellent local control (Hammer et al., 1994).
Radical surgery and postoperative radiation therapy are the accepted
methods of treatment for more advanced lesions of the external auditory
canal and lesions in the middle ear and mastoid. Tumors that are detected
early, each modality is considered optimal by itself, and a combination of
Management of Temporal Bone Malignancy
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Radiotherapy and Stereotactic Radiosurgery in Temporal Bone Malignancy
the two produces the best results in locally advanced disease (Chao et al.,
2008)
General management in middle ear malignancy
In management of temporal bone tumors originating from the middle
ear and mastoid area, surgeons have extended their abilities to resect tumors
in these areas owing to advances in surgical techniques, modern
neurosurgical anesthesia, intensive care, microsurgery, and cranial base
reconstruction with micro vascular flaps (Sekhar et al., 1992).
Depending
on
the
tumor
extent,
the
surgical
options
are
mastoidectomy, lateral temporal bone resection, subtotal temporal bone
resection, and total temporal bone resection. Postoperative radiation therapy
is essential to increase the chance of local tumor control. In studies that
suggest limited benefit of postoperative irradiation, the results may be
related to the extent of the tumor. Some investigators favor only limited
surgery and postoperative irradiation (Prasad & Janecka 1994).
Radiation Therapy Techniques
Before 1989, a single lateral field in mixed beam technique photon:
electron or most frequently, a paired lateral wedged technique was employed
for radiation treatment to achieve a better dose distribution (Wang 1975).
Since 1989, External beam radiation therapy (EBRT) has been
performed by an individualized radiation technique based on CT treatment
planning. From 1989 to 1995, dose distributions in multiple sections
throughout the target volume were calculated by Oncology Support System
Management of Temporal Bone Malignancy
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Radiotherapy and Stereotactic Radiosurgery in Temporal Bone Malignancy
(Philips), since 1995 true 3D-planning is performed using Treatment
Management System (Helax) (Pfreundner et al., 1999).
Target volume for treatment of cancer of the EAC includes the
petrosal bone, the parotid fossa, including intra- and infraparotideal lymph
nodes, ipsilateral retroauricular, upper jugular, and upper spinal accessory
lymph nodes. In case of clinical and histological confirmed lymph node
metastases, the target volume also includes the locations of the middle and
lower groups of the ipsilateral jugular and spinal accessory lymph nodes. In
case of histopathological confirmed perineural tumor spread along the facial
nerve, the compartment innervated by the ipsilateral facial nerve will be
included into the target volume (Pfreundner et al., 1999).
Using external beam radiation based on 3D CT-treatment planning, in
tumoricidal doses can be administered without a serious threat of brain stem
damage and brain injury. The radicality of resection and radiotherapy is a
factor influencing local control and survival. Postoperative adjuvant
radiotherapy with doses of 54–60 Gy when tumor was resected radically
could achieve a good local control and 5-year survival rate. Many cases of
late stage cancer of the external auditory canal and middle ear is resected
with tumor beyond surgical margins, also with reduced doses in
postoperative radiation treatment; this might be the reason for low local
tumor control rates. (Shih and Crabtree, 1990).
Tumors involving the pinna can be treated with electron beam. The
fields can be round or polygonal, drawn around the tumor to spare
surrounding normal tissues. For small superficial tumors, margins of 1 cm
are adequate. However, more extensive lesions require large portals, which
Management of Temporal Bone Malignancy
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Radiotherapy and Stereotactic Radiosurgery in Temporal Bone Malignancy
may encompass the entire pinna or external canal and require 2-3cm margins
around the clinically apparent tumor. Lesions involving the pinna must be
treated with low fractionation (1.8 to 2 Gy daily) to prevent cartilage
necrosis. Doses of 65 Gy over a period of 6.5 weeks are required to achieve
adequate tumor control (Chao et al., 2008).
Figure 39: Example of treatment portal for tumor of the middle ear involving the petrous
bone. The mastoid is included in the irradiated volume (Chao et al., 2008).
Large lesions of the external auditory canal are treated with irradiation
alone or combined with surgery; the portals should encompass the entire ear
and temporal bone with an adequate margin (3 cm). The volume treated
should include the ipsilateral preauricular, postauricular, and subdigastric
lymph nodes. Treating lymphatics beyond the jugulodigastric area is usually
not necessary. Extremely advanced tumors that are unresectable should be
treated with high-energy ipsilateral electron beam therapy (16 to 20 MeV)
alone or mixed with photons (4 to 6 MV) or with wedge pair (superior
inferiorly angled beams) techniques using low-energy photons. Doses of 60
to 70 Gy over 6 to 7 weeks are required. Doses higher than this may produce
Management of Temporal Bone Malignancy
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Radiotherapy and Stereotactic Radiosurgery in Temporal Bone Malignancy
osteoradionecrosis of the temporal bone. If various types of radiation therapy
beams are available, individualized treatment plans should be devised.
Patients receiving radiation therapy to the middle ear and temporal bone
regions require immobilization devices to avoid target miss. When electron
beam radiation therapy is used, use of water bolus in the external auditory
canal and concha may reduce the auricular complications. Threedimensional conformal radiation therapy is a valuable technique in the
treatment of these tumors (Chao et al., 2008).
This volume will be irradiated by a dose of 54–60 Gy. In case of
tumor involved surgical margins or residual tumor, boost volume will
include the site of the primary tumor and of the lymph node metastases.
Boost irradiation will be up to a total dose about 70 Gy (Chao et al., 2008).
Management of Temporal Bone Malignancy
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Radiotherapy and Stereotactic Radiosurgery in Temporal Bone Malignancy
Figure 40: Radiation technique for treatment of T3N1 carcinoma of the external auditory
canal with involvement of an intraparotideal lymph node and perineural tumor spread
along the facial nerve. The peripheral margin of facial nerve was infiltrated by the tumor.
(a) Three-field 5 MV-technique for treatment of potential tumor invaded structures
(applied dose 56 Gy, single dose 2 Gy). The fields from 273° to 337° are forming the
triangular dose distribution predescribed by the planning-target volume. The field from 0
degree is filling up the dose in the depth, and spares the brain stem. All fields are wedged
for homogenization of the dose distribution, field from 337° with the tip in cranial
direction. It compensates the dose loss caused by the increase of the patient’s diameter.
(b) Three-field wedged technique (290°, 230°, 0°), forming a triangular dose distribution
covering the tumor bed for boost irradiation (applied dose 14 Gy, single dose 2 Gy)
(Pfreundner et al., 1999).
Extension of the disease beyond the dura mater is a sign of
unresectability and incurability. Therefore, the palliative EBRT appears to
be the adapted treatment for these patients. Recurrences after surgery and
EBRT exhibit a poor prognosis. Brachytherapy is a treatment option which
can be applied in curative intent when the disease is locally confirmed.
Many authors concluded that brachytherapy can be used to achieve local
control in small volume recurrences at previous irradiated sites (Martinez et
al., 1991).
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Radiotherapy and Stereotactic Radiosurgery in Temporal Bone Malignancy
Figure 41: Dose distribution for brachytherapy treatment of EAC recurrence. 3D CTbased treatment was performed after surgery and a full course of EBRT (70 Gy). A mold
containing seven applicators was inserted in the cavity of resection. The reconstructed
applicator model is superimposed on the planning CT study. The target volume is defined
in the CT scans. (a) Planning-target volume and dose distribution in the region of the
upper border of the cavity of resection. (b) Planning-target volume and dose distribution
at the level of the mandibular joint. The 2 Gy isodose corresponds to the reference
isodose. (c) 3 D-patient model with the reference isodose surrounding the target volume
(Pfreundner et al., 1999).
Management of Temporal Bone Malignancy
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Radiotherapy and Stereotactic Radiosurgery in Temporal Bone Malignancy
Palliative Radiation Therapy
Radiation therapy offers significant palliation in recurrent or advanced
disease. Pain relief is reported in 61% of patients with tumors of the auditory
canal and middle ear. Recurrences developing after previous irradiation may
be retreated with low-dose radiation therapy and hope for control of tumor.
When a small-volume local recurrence occurs after previous radiation
therapy, fractionated high dose-rate treatment may be considered (Martinez
et al., 1991).
Results of radiotherapy
The series of patients reported from several institutions are small. In
more extensive lesions, combinations of surgery and irradiation have yielded
satisfactory results. Overall 5-year survival rates with combination therapy
for tumors involving the middle ear and external auditory canal range from
40% to 60%, with patients with earlier-stage tumors achieving a 70%
survival rate at 5 years with no evidence of disease (Hammer et al., 1994).
Sequelae of radiotherapy
Radiation therapy sequelae include cartilage necrosis of the external
auditory canal and osteoradionecrosis of temporal bone. Very rarely,
secondary infection and meningitis are reported. Because of the proximity of
the brainstem and medulla oblongata, it is extremely difficult to deliver a
high dose of irradiation to the temporal bone without a significant risk of
injury to these structures. An overall 10% incidence of bone necrosis can be
expected after administration of 60 to 65 Gy. After external ear lesions are
treated with interstitial irradiation, there is a 4% incidence of late cutaneous
Management of Temporal Bone Malignancy
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Radiotherapy and Stereotactic Radiosurgery in Temporal Bone Malignancy
and cartilage necrosis. Risk of necrosis increases for lesions over 4 cm
(Chao et al., 2008).
Stereotactic Radiosurgery
Stereotactic radiosurgery and radiotherapy are techniques to
administer precisely directed, high-dose irradiation that tightly conforms to a
target to create a desired radiobiologic response while minimizing radiation
dose to surrounding normal tissue (Mendenhall et al., 1996).
Stereotactic radiosurgery evolved from the pioneering work reported
in 1908 by Horsley and colleagues. They developed a tool that could localize
an intracranial structure in three dimensions, enabling the insertion of a
needle electrode. Using this apparatus in a monkey brain, Horsley and
Clarke were the first to describe the stereotactic destruction of an intracranial
target using electrode electrocoagulation (Horsley and Clarke, 1908).
Spiegel and colleagues began developing the first stereotactic device
for human use in 1947. Their device was fixed to the patient’s head in much
the same way as Horsley and Clarke’s (Spiegel et al., 1947).
Lars Leksell is known as the father of stereotactic radiosurgery for his
pioneering work applying the stereotaxic technique to radiation delivery.
Leksell1 developed his stereotactic apparatus for intracerebral surgery in
1947. The device enabled the precise placement of a needle or electrode into
a desired location within the human brain. Leksell first described the concept
of stereotactic radiosurgery in 1951. The initial device used a collimated xray beam (gamma rays) that could move along the semicircular arch of his
stereotactic apparatus to strike an intracranial target (Leksell, 1951).
Management of Temporal Bone Malignancy
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Radiotherapy and Stereotactic Radiosurgery in Temporal Bone Malignancy
In 1960, Leksell and colleagues performed their first human
stereotactic proton beam operation at the Gustaf Werner Institute in Uppsala.
About the same time, Woodruff and colleagues introduced a similar
cyclotron-based radiosurgery system and began irradiating pituitary lesions.
Leksell eventually settled on gamma rays as a practical compromise for
stereotactic radiosurgery. The first gamma unit was installed in Sweden, in
1968. The device used 179 sources of cobalt-60 distributed with collimators
to create a sharply circumscribed disc-shaped lesion. The second gamma
unit was installed in Stockholm, Sweden, in 1974. This updated version was
designed specifically for stereotactic radiosurgery (Leksell et al., 1960;
Woodruff et al., 1984; Leksell, 1983).
Target localization improved dramatically when CT was used in
conjunction with the stereotactic apparatus. Leksell described the application
of CT during radiosurgery and noted the technique enabled rapid and
accurate target localization. With the advent of better imaging methods,
solid tumors became radiosurgical targets. Leksell believed stereotactic
radiosurgery was a logical approach to decrease the morbidity and mortality
if compared to surgery (Leksell et al., 1980).
By 1985, Leksell and colleagues reported the potential application of
MRI to radiosurgery, pointing out the many advantages of this detailed
imaging modality (Leksell et al., 1985).
Today CT, MRI, and angiography are used commonly during
radiosurgical planning (Lasak & Gorecki, 2009).
So we have a treatment option, that could be stereotactic radiosurgery
or stereotactic radiotherapy (fractionated stereotactic radiosurgery). It is used
Management of Temporal Bone Malignancy
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Radiotherapy and Stereotactic Radiosurgery in Temporal Bone Malignancy
in patients who are not candidates for resection because of preference,
infirmity, or age (65 years or older). So they can be treated with either
external beam radiotherapy or stereotactic radiosurgery. In general,
stereotactic radiosurgery is preferred, because it is probably at least as
effective as fractionated external beam irradiation and is considerably less
time consuming. The risk of a major complication after stereotactic
radiosurgery is probably similar to that associated with external beam
irradiation. There is considerable interest in the development of stereotactic
radiotherapy, in the hope of achieving local control rates comparable with
those obtained by both external beam irradiation and stereotactic
radiosurgery but with less morbidity. This is a reasonable option for the
elderly patient in poor health with a limited tumor (Mendenhall et al.,
1996).
Radiation therapy techniques
Stereotactic radiosurgery may be delivered with a particle beam, a
gamma knife, or a linear accelerator. The cost associated with particle beam
therapy is more than for the gamma knife or linear accelerator.
Disadvantages of the gamma knife are that it is also expensive, it requires
201 cobalt-60 sources that must be replaced periodically, and it can only be
used for stereotactic radiosurgery. The linear accelerator based system is an
effective method of delivering stereotactic radiosurgery and is much less
expensive than the other two alternatives. An additional advantage is that the
linear accelerator can be used for conventional external beam irradiation
when it is not being used for radiosurgery. The Brown-Roberts-Wells
(BRW) frame is attached to the patient's skull. A stereotactic CT with or
without MRI is then obtained in the axial plane and is used to plan the
Management of Temporal Bone Malignancy
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Radiotherapy and Stereotactic Radiosurgery in Temporal Bone Malignancy
treatment. Stereotactic radiosurgery is delivered with 6 MV X-rays using
multiple noncoplanar arcs (Mendenhall et al., 1996).
Figure 42: Stereotactic radiosurgery technique
(A, B) Treatment is delivered through up to nine non coplanar arcs intersecting at the
isocenter of the target.
(C) The location of the arcs relative to the calvarium is indicated (Friedman et al.,
1992).
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Radiotherapy and Stereotactic Radiosurgery in Temporal Bone Malignancy
In 1997, Adler introduced the Cyberknife. It is a frameless stereotactic
radiotherapy system that mounts a lightweight (130 lb) 6 mV linear
accelerator on a highly mobile robotic arm. This revolutionary design
incorporates a real-time guidance system, which obviates the need for rigid
fixation as used in frame base systems. Cyberknife determines the location
of the skull or spine in the coordinate frame of the radiation delivery system
by comparing digitally reconstructed CT phantoms obtained from the
patient’s treatment planning images with real-time oblique radiographs
obtained during the procedure. (Chang and Adler, 2001).
Figure 43: John Adler and the Cyberknife (Lasak & Gorecki, 2009).
Management of Temporal Bone Malignancy
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Radiotherapy and Stereotactic Radiosurgery in Temporal Bone Malignancy
Now, the medical community has a well-founded combination of
anticipation and expectation for noninvasive treatment methods. The
potential for decreased morbidity and improved quality of life with the use
of radiosurgery and radiotherapy is being realized. There is a growing
involvement outside of neurosurgery and radiation oncology, such as
neurotologists, thoracic surgeons, general surgeons, and urologists.
Stereotactic radiosurgery and radiotherapy will continue to advance
treatment options for patients, and the future of this evolving field should be
interesting (Lasak & Gorecki, 2009).
Chemotherapy
The role of chemotherapy in the treatment of temporal bone
malignancy has not been determined, but interest in its use is growing.
Because of the low incidence and the histologic diversity of temporal bone
malignancies. Temporal bone malignancies of salivary gland origin, similar
to salivary malignancies in other sites, do not usually respond to currently
available chemotherapeutic agents. Squamous cell carcinoma of the
temporal bone may respond to platinum-based agents, but typically the
results are not durable, and other modalities must be used. For these reasons,
most patients with temporal bone cancer are treated with surgery, radiation,
or a combination of the two, and chemotherapy is usually reserved for
palliation in patients with distant metastases or recurrences (Arriaga and
Leonetti, 2010)
Chemotherapy has been shown to be effective for rhabdomyosarcoma
(Leonetti and Marzo, 2002).
Management of Temporal Bone Malignancy
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Radiotherapy and Stereotactic Radiosurgery in Temporal Bone Malignancy
Nakagawa and others, published data that suggest a possible role for
preoperative chemoradiation therapy in the treatment of T3 and T4
squamous cell carcinoma. The radiation-enhancing effect of chemotherapy
may be useful in reducing the tumor burden and improving control of the
surgical margin. They showed improved survival rates for T4 lesions not
involving dura, pyramidal apex, carotid canal, or lymph nodes that are as
good as survival rates in patients with T3 lesions (Nakagawa et al., 2006).
Management of Temporal Bone Malignancy
101
Prognosis and Outcome
of
Temporal Bone Malignancy
Prognosis and Outcome of Temporal Bone Malignancy
It is difficult to meaningfully compare the treatment outcome of
temporal bone malignancy for several reasons. Temporal bone malignancy is
so rare that no one center has extensive experience with treatment. Lack of
universally accepted staging systems and the wide variety of treatment
protocols applied make comparison of results difficult. No prospective study
comparing different treatment protocols has been carried out as yet (Moffat,
2009).
The local extent of tumor at diagnosis is an important prognostic
indicator. In most studies the cure rate is high when the disease is lateral to
the tympanic membrane. When disease is detected early and limited to the
external canal a lateral temporal bone resection can be performed. More
extensive disease extending into the middle ear and surrounding structures
including dura, brain, pterygoid muscles, otic capsule, and carotid carries a
worse prognosis and hence the extent of surgery must be according to the
disease stage (Moffat, 2009).
However, if the disease is confined to the EAC. No statistically
significant difference in 5-year survival was found between patients treated
with LTBR and patients treated with STBR. When disease extended into the
middle ear, patients who had STBR had better 5-year survival than patients
who had LTBR. The experience with carcinoma that invaded the petrous
apex is limited. But patients then will be treated with TTBR (Prasad and
Janecka, 2010)
Regarding the value of preoperative or postoperative radiation
therapy, when the disease is confined to the EAC, the addition of either
preoperative or postoperative radiation therapy to LTBR did not
Management of Temporal Bone Malignancy
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Prognosis and Outcome of Temporal Bone Malignancy
significantly improve 5-year survival. But in more aggressive disease,
radiotherapy has a vital rule for local control and improving the survival rate
(Prasad and Janecka, 2010).
When the disease extends into the middle ear a lateral temporal bone
resection will offer a 28.7% survival rate. Whereas a more extensive subtotal
temporal bone resection has a 41.7% five-year survival. More recently the
cure rates for T3 and T4 tumors are reported between 35–47% (Moffat et al.,
2005).
This highlights the importance of aggressive en bloc resection. Moffat
in an early review in 1997 reported his data on 15 patients who underwent
either a lateral temporal bone resection or for more advanced disease
extended temporal bone resection. He achieved an overall outcome of 47.5%
five-year survival.
A more recent review in 2005 of 39 patients revealed that survival for
stage I and II disease was 100% and for stage III and IV disease was 43%.
This again demonstrated the increased survival of early stage disease and the
importance of early diagnosis and aggressive surgical management (Moffat
et al., 2005).
Moffat and Moody both recommend an en bloc resection and Moody
proposes that a prospective protocol be developed in which each skull base
unit follows a progression of treatment that is specific for each stage of the
disease based on a consistent staging system. For early lesions a modified
temporal bone resection or a lateral temporal bone resection (LTBR) is
performed, with more advanced lesions a subtotal temporal bone resection
(STBR) or a total temporal bone resection (TTBR) should be the treatment
Management of Temporal Bone Malignancy
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Prognosis and Outcome of Temporal Bone Malignancy
of choice. Moffat takes a more aggressive approach than this and states that
the minimal procedure for disease lateral to the tympanic membrane should
be a LTBR and superficial parotidectomy. For T3 and T4 disease an
extended temporal bone resection and total parotidectomy with facial nerve
sacrifice offers the greatest chance of cure.
Half the recurrences are in the first 12 months following treatment and
85% of recurrences occur within three years of treatment. Recent evidence
suggests that treatment for advanced and recurrent cancer in the form of
extended temporal bone resection and postoperative radiotherapy results in
improved five-year survival rates of 47% (Moffat et al., 1997).
Specific Outcome Issues
Nodal Disease
Twenty-three percent of the 39 patients in Moffat’s series had nodal
disease at presentation, confirmed by histology following radical neck
dissection. He considered that this was a significant prognostic indicator in
his series. Death was always due to local recurrence and hence it was
believed that nodal disease is a good indicator of aggressive disease (Moffat
et al., 2005).
Histology
Generally undifferentiated tumors had a poorer prognostic outcome
than moderately and well-differentiated tumors. Positive histological
margins at the time of resection, not surprisingly, are a poor prognostic
indicator in this locally aggressive disease. Death in these patients usually
occurs within 12 months (Moffat et al., 2005).
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Prognosis and Outcome of Temporal Bone Malignancy
Basal cell carcinoma has a propensity for deep local invasion and
perineural spread with metastases being rare. Primary melanoma of the
temporal bone is extremely rare with a very poor prognosis (Moffat et al.,
2009).
Adenoid cystic carcinomas are the most common glandular tumors.
Adenocarcinomas are usually well differentiated low-grade papillary
cancers. The long-term prognosis for high-grade adenocarcinoma and
mucoepidermoid carcinoma is poor. In contrast, survival after adenoid cystic
carcinoma can be lengthy even in the presence of metastases (Glasscock et
al., 1987).
Chondrosarcoma of the temporal bone is extremely rare. These tumors
may be indolent and present late. They tend to invade locally and
metastasize late. They may extend outside the temporal bone and into the
cerebellopontine angle. Radical surgery and postoperative radiotherapy is
the treatment of choice (Moffat et al., 2009).
Rhabdomyosarcoma is a rare aggressive tumor almost exclusively
limited to childhood age groups. The mean age at presentation is five years.
Until recently the prognosis has been extremely poor, but following the
multimodality treatment (surgical resection, followed by radiotherapy and
chemotherapy)
protocol
recommended
by
The
Intergroup
Rhabdomyosarcoma Study Committee, treatment outcomes have greatly
improved. Recurrent sarcoma tends to spread early to the lungs and bone,
and intracranially to involve multiple cranial nerves (Wiatrak and Pensak,
1989).
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Prognosis and Outcome of Temporal Bone Malignancy
Dural and Cerebral Involvement
Brain involvement is usually associated with a poor outcome. In
Moffat’s series dural involvement alone was not a significant prognostic
indicator. (Moffat et al., 2005).
Carotid Invasion
Invasion of the carotid artery signifies extensive disease progression.
Both Gillespie and Moffat no longer consider carotid resection. In the series
described by Moffat of the seven patients with perivascular involvement of
the carotid, only one is alive at a follow up of six months. Gillespie reports
two patients with carotid involvement both of whom have died of their
disease within months of treatment. Moody successfully resected the carotid
in one patient who is still alive, but no comment was made with regards to
neurological status in this case (Gillepsie et al., 2001).
De Novo versus Salvage
If patients had undergone any treatment at any institution, so any
further treatment is considered salvage. Patients with no previous treatment
are defined as de novo cases. Although the numbers were too small to make
any statistical analysis the trend showed poorer outcomes for the salvage
patients. This would support the concept that the first treatment protocol
offers the greatest chance of cure and should be aggressive (Moffat et al.,
2009).
Management of Temporal Bone Malignancy
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Report of a case
Report of a case
A 21 year old man presented to kasr Al Aini university hospital with
long history of unresolved chronic suppurative otitis media with left facial
paralysis. The patient was underwent left ear exploration. Abnormal tissue
was seen during the operation, so radical mastoidectomy was done and
biopsy was taken for histopathological examination. The result showed
squamous cell carcinoma.
Figure 44: Close up view
showing the lateral extent of
the mass encroaching on the
concha.
After that, CT scan was done revealed destructive lesion involving the
left external auditory canal, middle ear, mastoid and reaching the petrous
apex short of the carotid artery, with erosion of the tegmen tympani. No
intracranial extension was found.
According to that, he was staged T4 N0 temporal bone squamous cell
carcinoma.
Management of Temporal Bone Malignancy
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Report of a case
He underwent left total temporal bone resection.
Figure 45: Operative view
showing markings including:
1. The incision.
2. Temporalis
muscle
borders.
3. Zygomatic arch.
4. Mandible.
5. Sternomastoid muscle and
trapezius.
6. Mastoid process.
Figure 46: Intraoperative view
showing the incision.
Note: preservation of the auricular
framework.
Management of Temporal Bone Malignancy
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Report of a case
Figure 47: Intraoperative view
showing anterior and posterior
flap elevations before surgical
dissection.
Figure 48: Intraoperative view
after neck dissection and temporal
craniotomy showing:
1. Temporalis muscle.
2. Outline
of
temporal
craniotomy.
3. Outline of specimen before
resection.
4. Cut facial nerve (tagged).
5. Cut internal jugular vein
(tagged).
Management of Temporal Bone Malignancy
109
Report of a case
Figure 49: Intraoperative view after resection showing: 1) Temporal lobe dura.
2) cerebellum. 3) Internal carotid artery. Note: the lower four cranial nerves are
numbered.
Management of Temporal Bone Malignancy
110
Report of a case
Figure 50: The specimen (lateral aspect).
Figure 51: Immediate postoperative view. Note marginal skin ischemia of the auricle
that resolved completely after 1 month.
Management of Temporal Bone Malignancy
111
Report of a case
Postoperative radiation therapy was done and ended in December
2007.
Follow up CT was done every three months for the first year, then
every six months in the second year with no evidence of recurrence.
After thirty months, there is no evidence of recurrence and he is at the
present time a candidate for dynamic facial reanimation using free muscle
flap.
Management of Temporal Bone Malignancy
112
Summary
Summary
The temporal bone is a composite structure consisting of the tympanic
bone, mastoid process, squama (also known as the squamous portion of the
temporal bone), and petrosa (also known as the petrous portion of the
temporal bone). Although the styloid process is closely related to the
temporal bone, it is not considered a portion of it.
It contains the structures of the middle ear and inner ear. Also it is
related to vital structures as the temporal lobe and the internal carotid artery.
According to different histological structures in the temporal bone
there are many tumors could arise either from external auditory canal or the
middle ear. Carcinomas as squamous cell carcinoma, basal cell carcinoma,
malignant melanoma and adenexal carcinomas. Sarcomas as angiosarcoma,
chondrosarcoma and rhabdomyosarcoma. Each type has its own behavior
and presentation.
Malignant tumors of temporal bone could spread directly to involve
surrounding tissues as parotid gland anteriorly through fissures of santorini.
Superiorly to involve temporal lobe, deeply to involve middle ear structures
facial nerve and inner ear reaching to the internal carotid and petrous apex.
In general, temporal bone malignancy has low incidence of lymphatic
and distant metastasis but if present it carries very poor prognosis.
Age incidence in temporal bone malignancies usually above 60 years
except in case of rhabdomyosarcoma that present in younger age groups.
The presentation is usually in the form of bloody otorhea, hearing loss
or aural polyp.
Management of Temporal Bone Malignancy
113
Summary
On examination we can see suspicious granulations that bleed on
touch or tumor mass itself.
For accurate diagnosis of temporal bone malignancies biopsy must be
taken from the suspicious polyp or tumor mass. Also computed tomography
and magnetic resonance imaging play very important rule in tumor staging
to know extensions of the tumor if vital structures as internal carotid artery is
affected or not. Also MRI is superior on CT in diagnosing soft tissue
involvement and perinural spread of tumors. Magnetic resonance
angiography can be done also to detect carotid and big vessel affection.
Recently fusion between CT and MRI is used for better visualization of
temporal bone tumors.
Management of malignant tumors of temporal bone could be through
surgery, radiotherapy or a combination of both.
The role of chemotherapy is generally limited and it is beneficial only
in case of rhabdomyosarcoma. It is used also for palliation to control distant
metastasis.
The treatment program depends primarily on the extent of the cancer.
Cancer limited to the EAC (T1, T2) should be treated by lateral temporal
bone resection with superficial parotidectomy and preservation of the facial
nerve. Rarely, the cancer may be small, isolated in the lateral cartilaginous
aspect of the EAC, and not eroding bone, thereby permitting sleeve resection
of the external canal skin, lateral to the tympanic membrane. In practice,
sleeve resection is probably not oncologically adequate.
Management of Temporal Bone Malignancy
114
Summary
Cancer that has invaded the middle ear and mastoid cavities (T3) is
treated by subtotal temporal bone resection. Total temporal bone resection
(sometimes called Radical temporal bone resection) is performed when
cancer
extends
to
the
petrous
apex.
Cancer
extending
to
the
temporomandibular joint (TMJ), neck, dura, or Infratemporal fossa (T4) will
require resection of these structures.
Radiotherapy is essential in the treatment of temporal bone
malignancy especially if combined with surgery for adequate local control of
the disease. It improves the prognosis of large lesions, in case of positive
margins and in recurrence after surgery.
Stereotactic radiosurgery is used for treatment of limited tumors not
more than 5 cm. It represents a new non invasive line of treatment with
decreased morbidity.
It is difficult to determine adequate outcome of treatment of temporal
bone malignancy for several reasons. Temporal bone malignancy is so rare
that no one center has extensive experience with treatment. Lack of
universally accepted staging systems and the wide variety of treatment
protocols applied make comparison of results difficult. Generally,
undifferentiated tumors give poor prognosis. The survival rate will be
affected according to the type and invasion of the tumor to the surrounding
structures. Recurrence after surgery and radiotherapy gives very bad
prognosis.
Management of Temporal Bone Malignancy
115
References
References
Afzelius L-E. and Gunnarsson M.H.N. (1980): Guidelines for
prophylactic radical lymph node dissection in cases of carcinoma of the
external ear. Arch. Otolaryngol Head Neck Surg.; 2: 361.
Ahmad I. and Gupta A.R. (2001): Epidemiology of basal cell carcinoma
and squamous cell carcinoma of the pinna. Journal of Laryngology and
Otology; 115: 85–86.
Ahuja A.T., Yuen H.Y., Wong K.T., Yue V., Vanhasselt A.C. (2003):
Computed Tomography Imaging of the Temporal Bone, Normal
Anatomy. Clinical Radiology 58: 681–686
Alcedo J.C., Fabrega J.M., Arosemena J.R. and Urrutia A. (2004):
Imatinib mesylate as treatment for adenoid cystic carcinoma of the
salivary glands: report of two successfully treated cases. Head & Neck;
26: 829–31.
Arena S. and Keen M. (1988): Carcinoma of the middle ear and
temporal bone. Am. J. Otolaryngol.; 9(5): 351-365
Ariyan S., Sasaki C.T. and Spencer D. (1981): Radical en bloc resection
of the temporal bone. American J of Surgery; 142: 443-447
Arriaga M. A. and Leonetti J. P. (2010): Malignancies of the Temporal
Bone-Limited Temporal Bone Resection. Otologic surgery by Derald E.
Brackmann, Clough Shelton and Moisés A. Arriaga 3rd edition chapter 3
Aslan A., Falcioni M. and Balyan F.R. (1998): The cochlear aqueduct:
an important landmark in lateral skull base surgery. OtolaryngologyHead & Neck Surgery; 118: 532-536.
Avila J., Bosch A. and Aristizabal S. (1977): Carcinoma of the pinna.
Cancer; 40: 2891.
Babuccu O., Kargi E., Hosnuter M. and Dogan B.G. (2003): Atypical
presentation of Kaposi’s sarcoma in the external ear. Kulak Burun Boğaz
İhtisas Dergisi; 11: 17-20.
Management of Temporal Bone Malignancy
116
References
Bambakidis N.C., Megerian C.A. and Ratcheson R.A. (2004):
Differential grading of endolymphatic sac tumor extension by virtue of
von Hippel-Lindau disease status. Otology and Neurotology; 25: 773781.
Barnes L., Eveson J., Reichart P. and Sidransky D. (2005): Pathology
and Genetics of Head and Neck Tumors, World Health Organization
Classification of Tumors; International Agency for Research on Cancer
(IARC); IARC Press, Lyon.
Barrs D. (2001): Temporal bone carcinoma, Otolaryngologic Clinics of
North America - Volume 34, Issue 6.
Bartling S.H., Peldschus K., Rodt T., Kral F., Matthies H., Kikinis R.,
and Becker H. (2005): Registration and Fusion of CT and MRI of the
Temporal Bone. Journal of Computer Assisted Tomography; 29: 305310.
Budd G.T. (2002): Management of angiosarcoma. Current Oncology
Report; 4: 515–519.
Butler P. and Wylie I.G. (1999): The ear and auditory pathways. In:
Butler P., Mitchell A.W.M. and Ellis H. editions. Applied Radiological
Anatomy, 1st edition. Cambridge University Press, Cambridge, UK: 8594.
Carey J.P., Minor L.B. and Nager G.T. (2000): Dehiscence or thinning
of bone overlying the superior semicircular canal in a temporal bone
survey. Archive of Otolaryngology Head & Neck Surgery; 126: 137-147.
Castillo M., Serda R., Barnadas Molins B., Arti P., Claramunt C.,
Perello Scherdel E. (2000): Facial paralysis of metastatic origin. Review
of metastatic lesions of the temporal bone. Annals Otorrinolaringology
Ibero America 27: 255-263.
Management of Temporal Bone Malignancy
117
References
Chakeres D.W. and Augustyn M.A. (1996): Temporal bone: imaging. In:
Som P.M. and Curtin H.D. editions. Head and Neck Imaging, 4th edition.
St Louis, MO, USA, Mosby; 1093-1108.
Chang S.D. and Adler J.R. (2001): Robotics and radiosurgery.
Stereotactic and Functional Neurosurgery; 76: 204-208.
Chao K.S.C. and Devineni V.R. (2008): Ear. Perez and Brady's
Principles and Practice of Radiation Oncology, 5th Edition Chapter 36 by
Halperin E.C., Perez C.A. and Brady L.W.
Chee G., Mok P. and Sim R. (2000): Squamous Cell Carcinoma of
theTemporal Bone: Diagnosis, Treatment and Prognosis. Singapore
Medical J; 41(9): 441-446,451
Chung S.J. and Pensak M.L. (2005): Tumors of the temporal bone.
Neurotology 2nd edition: 1028-1036
Cole M.D., Jakowatz J. and Evans G.R. (2003): Evaluation of nodal
patterns for melanoma of the ear. Plastic and Reconstructive Surgery;
112: 50-56.
Cole MD. Jakowatz J. and Evans GR. (2003): Evaluation of nodal
patterns for melanoma of the ear. Plast Reconstr Surg; 112: 50–56.
Conley J. (1965): Cancer of the Middle Ear. Annals of Otolaryngology;
74: 555-572
Curtin H.D., Sanelli P.C. and Som P.M. (1996): Temporal bone:
embryology and anatomy. In: Som P.M. and Curtin H.D. editions. Head
and Neck Imaging, 4th edition. St Louis, MO, USA, Mosby: 1057-1091.
Curtin H.D., Williams R. and Johnson J. (1985): CT of the perineural
tumor extension- pterygnpalatine fossa. American Journal of
Roentgenology; 144: 163-169.
Curtin H.D., Wolfe P. and Snyderman N. (1983): Facial nerve between
the stylomastoid foramen and parotid: CT imaging. Radiology; 149: 165169.
Management of Temporal Bone Malignancy
118
References
De Foer B., Kenis C., Vercruysse J-P., Somers T., Pouillon M.,
Offeciers E., and Casselman J.W. (2009): Imaging of Temporal
BoneTumors. Neuroimaging Clinics of North America; 19: 339-366
De Vries E.J., Sethar L.N. and Horton J.A. (1990): A new method to
predict safe resection of the internal carotid artery. Laryngoscope; 100:
85-88
Delbrouck C., Kampouridis S. and Chantrain G. (1998): An unusual
localisation of Kaposi’s sarcoma: the external auditory canal. Acta
Otorhinolaryngology Belgium; 52: 29-36.
Devaney K., Boschman C., Willard S., Ferlito A. and Rinaldo A.
(2005): Tumours of the external ear and temporal Bone; a review. Lancet
Oncology; 6: 411-420
Dimopoulos M.A.and Hamilos G. (2002): Solitary bone plasmacytoma
and extramedullary plasmacytoma. Current Treatment Options in
Oncology; 3: 255-259.
Doubleday L.C., Jing B.S. and Wallace S. (1981): Computed
tomography of the infratemporal fossa. Radiology; 138: 619-624.
Driscoll C.L.W. and Lane J.I. (2007): Advances in Skull Base Imaging.
Otolaryngology Clinics of North America; 40: 439-454
Durve D.V., Kanegaonkar R.G., Albert D. and Levitt G. (2004):
Paediatric rhabdomyosarcoma of the ear and temporal bone. Clinical
Otolaryngology; 29: 32-37.
Ellul S., Shelton C. and Davidson H.C. (2000): Preoperative cochlear
implant imaging: is magnetic resonance imaging enough? Am. J.
Otolaryngol.; 21: 528-533.
Eshraghi A.A., Buchman C. and Telischi F.F. (2001): Facial nerve
branch to the external auditory canal. American Neurotology Society,
Annual
Meeting
abstracts.
http://itsa.ucsf.edu/~ajo/ANS/ANSspr21ab.html.
Management of Temporal Bone Malignancy
119
References
Figi A. and Hempstead B.E. (1943): Malignant Tumors of the Middle
Ear and the Mastoid Process. Archive of Otolaryngology; 37: 149-194
Fish B.M., Huda R., Dundas S.A. and Lesser T.H. (2002): B-cell
lymphoma of the external auditory meatus. Journal of Laryngology and
Otology; 116: 39-41.
Friedan W.A., Bova F. J. and Spiegelmann R. (1992): Linear
accelerator radiosurgery at the University of Florida. Neurosurgery
Clinics of North America; 3: 141-166
Gacek M.R., Gacek R.R. and Gantz B.(1998): Pseudoepitheliomatous
hyperplasia versus squamous cell carcinoma of the external auditory
canal. Laryngoscope; 108: 620-623.
Gacek R.R. (1992): Evaluation and management of temporal bone
arachnoid granulations. Arch. Otolaryngol Head Neck Surg.; 118: 327332.
Gacek R.R. and Goodman M. (1977): Management of malignancy of the
temporal bone. Laryngoscope; 87: 1622-1634.
Gacek R.R. and Leipzig B. (1979): Congenital cerebrospinal fluid
otorrhea. Annuals of Otology, Rhinology & Laryngology; 88: 358-365.
Gacek RR. (1998): Anatomy and significance of the subarachnoid space
in the fallopian canal. Am. J. Otolaryngol.; 19: 358-364.
Gillepsie M.B., Francis H.W. and Chee N. (2001): Squamous cell
carcinoma of the temporal bone: a radiographic-pathologic correlation.
Arch. Otolaryngol Head Neck Surg.; 127: 803-807.
Glasscock M. E. and Gulya A. J. (2007): Glasscock-Shampaugh Surgery
of the Ear, 5th edition.
Glasscock M.E. III, McKennan K.X. and Levine S.C. (1987): Primary
adenocarcinoma of the middle ear and temporal bone. Arch. Otolaryngol
Head Neck Surg.; 113: 822-824.
Management of Temporal Bone Malignancy
120
References
Gloria-Cruz T.I., Schachern P.A., Paparella M.M., Adams G.L. and
Fulton S.E. (2000): Metastases to temporal bones from primary
nonsystemic malignant neoplasms. Arch. Otolaryngol Head Neck Surg.;
126: 209-214.
Goodwin W.J. and Jesse R.H. (1980): Malignant neoplasms of the
external auditory canal and temporal bone. Archive of Otolaryngology;
106: 675-679.
Graham M.D., Sataloff R.T. and Kemink J.L. (1984): Total enbloc
resection of the temporal bone and carotid artery for malignant tumors of
the ear and temporal bone. Laryngoscope; 94: 528-533
Gulya A.J. and Schuknecht H.F. (2007): Anatomy of the temporal bone
with surgical implications. 3rd ed. Pearl River (NY): Parthenon
Publishing Group, Inc.
Hammer J., Eckmayr A. and Zoidl J. (1994): Case report: Salvage
fractionated high dose rate after-loading brachytherapy in the treatment
of recurrent tumor in the middle ear. The British Journal of Radiology;
67: 504.
Hans P., Grant A.J. and Laitt R.D. (1999): Comparison of threedimensional visualization techniques for depicting the scala vestibuli and
scala tympani of the cochlea by using high-resolution MR imaging.
American Journal of Neuroradiology; 20: 1197-1206.
Hashia N., Shiratoa H., Omatsua T., Kageia K., Nishiokaa T.,
Hashimotoa S., Aoyamaa H., Fukudab S., Inuyamab Y. and Miyasakaa
K. (2000): The role of radiotherapy in treating squamous cell carcinoma
of the external auditory canal, especially in early stages of disease
Radiotherapy and Oncology; 56: 221-225
Hawkins D.S., Anderson J.R. and Paidas C.N. (2001): Improved
outcome for patients with middle ear rhabdomyosarcoma: a Children’s
Oncology Group study. Journal of Clinical Oncology; 19: 3073-3079.
Management of Temporal Bone Malignancy
121
References
Heiligenhaus A., Dutt J.E. and Foster C.S. (1996): Histology and
immunopathology of systemic lupus erythematosus affecting the
conjunctiva. Eye; 10: 425-432
Hill D.L., Hawkes D.J. and Gleeson M.J. (1994): Accurate frameless
registration of MR and CT images of the head: applications in planning
surgery and radiation therapy. Radiology; 191: 447-454.
Hinton D. (1974): Cancer of the Middle Ear and Mastoid Process.
Journal of the National Medical Association; 66(2): 125-128
Hirsch B.E., Chang C.Y.J., and Antonio S.M. (2008): Carcinoma of the
Temporal Bone. Operative Otolaryngology Head and Neck surgery by
Eugene N. Myers 2nd edition volume III; chapter 123:1271-1293
Horsley V. and Clarke R.H. (1908): The structure and functions of the
cerebellum examined by a new method. Brain; 31: 45-124.
Hughes G.B. and Pensak M.L. (1997): Clinical otology. 2nd edition.
New York: Thieme Medical Publishers.
Hunter R., Pereira D. and Pointon R. (1982): Megavoltage electron
beam therapy in the treatment of basal and squamous cell carcinomata of
the pinna. Clinical Radiology; 33: 341.
Jensen RL., Gillespie D., House P., Layfield L. and Shelton C. (2004):
Endolymphatic sac tumor in patients with and without von HippelLindau disease: the role of genetic mutation, von Hippel-lindau protein,
and
hypoxia
inducible
factor-1alpha
expression.
Journal
Neurosurgery;100: 488-497.
Keles B., Semaan M. and Fayad J. (2009): The medial wall of the
jugular foramen: A temporal bone anatomic study; Otolaryngology-Head
and Neck Surgery; 141: 401-407.
Kim H., Han M.H., Park S.W. and Cho Y.K. (2001):
Radiologicpathologic correlation of unusual lingual masses: Part II:
Benign and malignant tumors. Korean Journal of Radiology; 2: 42-51.
Management of Temporal Bone Malignancy
122
References
Kim H.F., Butman J.A. and Brewer C. (2005): Tumors of the
endolymphatic sac in patients with von Hippel-Lindau disease:
implications for their natural history, diagnosis, and treatment. Journal of
Neurosurgery; 102: 503-512.
Kinney S.E. (1989): Squamous cell carcinoma of the external auditory
canal. Am. J. Otolaryngol.; 10: 111-116
Kokemueller H., Eckardt A., Brachvogel P.and Hausamen J.E. (2004):
Adenoid cystic carcinoma of the head and neck; a 20 year experience.
International J of Oral & Maxillofacial Surgery; 33: 25-31.
Kveton J.F. (1996): Anatomy of the jugular foramen: the neurologic
perspective. Operative Techniques ORL-HNS; 7: 95-98.
Laine F.J., Braun I.F. and Jensen (1990): Perineural tumor extension
through the foramen ovale, Evaluation with MR imaging. Radiology;
174: 65-71.
Lang E.E., Walsh R.M. and Leader M. (2003): Primary middle-ear
lymphoma in a child. Journal of Laryngology and Otology; 117, p: 205207.
Lasak J.M. and Gorecki J.P. (2009): The History of Stereotactic
Radiosurgery and Radiotherapy. Otolaryngology Clinics of North
America; 42: 593-599
Lassaletta L., Patron M., Oloriz J. and Nasus A. (2003): Avoiding
misdiagnosis in ceruminous gland tumours. Larynx ; 30: 287-290.
Leblanc A. (1999): Internal ear and vestibulocochlear pathways, Organs
of hearing and balance. In: Leblanc A. edition. Atlas of Hearing and
Balance Organs, A Practical Guide for Otolaryngologists. France,
Springer- Verlag: 12-28.
Lederman M. (1965): Malignant tumors of the ear. J Laryngology &
Otology; 79: 85-119
Management of Temporal Bone Malignancy
123
References
Lehrer M.S., Hershock D. and Ming M.E. (2004): Merkel cell
carcinoma. Current Treatment Options in Oncology; 5: 195-199.
Leksell L. (1951): The stereotactic method and radiosurgery of the brain.
Acta Chirurgica Scandinavica; 102: 316-319.
Leksell L. (1983): Stereotactic radiosurgery. J of Neurology ,
Neurosurgery & Psychiatry; 46: 797-803.
Leksell L. and Jernberg B. (1980): Stereotaxis and tomography. A
technical note. Acta Neurochirurgica; 52(1-2): 1-7.
Leksell L., Larsson B. and Andersson B. (1960): Lesions in the depth of
the brain produced by a beam of high-energy protons. Acta Radiology;
54: 251-264.
Leksell L., Leksell D. and Schwebel J. (1985): Stereotaxis and nuclear
magnetic resonance. J of Neurology ,Neurosurgery & Psychiatry; 48: 1418.
Leonetti J.P., Sam J. and Marzo S.J. (2002): Malignancy of the
temporal bone. Otolaryngologic Clinics of North America; 35: 405-410
Lewis J. (1987): Cancer of the ear. CA cancer J.; 37: 78-86.
Liebross R.H., Ha C.S, and Cox J.D. (1999): Clinical course of solitary
extramedullary plasmacytoma. Radiotherapy & Oncology; 52:245-249.
Litofsky N.S., Smith T.W. and Megerian C.A. (1998): Merkel cell
carcinoma of the external auditory canal invading the intracranial
compartment. Am. J. Otolaryngol.; 19: 330-334.
Lonser R.R., Kim H.J. and Butman J.A. (2004) : Tumors of the
endolymphatic sac in von Hippel- Lindau disease. New England Journal
of Medicine; 350: 2481-2486.
Mancuso A.A., Bohman L., Hanafee W. and Maxwell D. (1980):
Computed tomography of the nasopharynx: normal and variants of
normal. Radiology; 137: 113-121.
Management of Temporal Bone Malignancy
124
References
Mansour P., George M.K. and Pahor A.L. (1992): Ceruminous gland
tumours: areappraisal. The Journal of Laryngology and Otology; 106:
727-732.
Markou F., Ilias Karasmanis I., John K. Goudakos, Papaioannou M.,
Psifidis A. and Victor Vital (2009): Extramedullary plasmacytoma of
temporal bone: report of 2 cases and review of literature, Am. J.
Otolaryngol.–Head and Neck Medicine and Surgery; 30: 360-365.
Martinez A., Edmundson G. and Borrego C. (1991): High dose rate
treatment of ear canal carcinoma: A case report. Activity; 1: 2-6.
Mazeron J-J., Ghalie R. and Zeller J. (1986): Radiation therapy for
carcinoma of the pinna using iridium 192 wires: a series of 70 patients.
International Journal of Radiation Oncology, Biology and Physics; 12:
1757.
Medina J.E., Park A.O., Neely J.G. and Britton B.H. (1990): Lateral
temporal bone resections. The American Journal of surgery; 160: 427433
Megerian C.A. and Semaan M.T. (2007): Otolaryngologic Evaluation
and Management of Endolymphatic Sac and Duct Tumors. Clinics of
North America; 40: 463-478
Mendenhall W.M., Friedman W.A., Parsons J.T., BuattiJ.M. and Bova
F.J. (1996): Radiation therapy and stereotactic radiosurgery for temporal
bone tumors. Operative Techniques In Otolaryngology-Head And Neck
Surgery; 7(2): 208-218
Moffat D.A. (2009): Management of Tumors of the Temporal Bone. In
Principles and Practice of Head and Neck Surgery and Oncology Second
edition by Paul Q. Montgomery, Peter H. Rhys Evans and Patrick J.
Gullane, chapter 21.
Moffat D.A., Chiossone-Kerdel J.A. and Da Cruz M. (2000): Squamous
cell carcinoma. In Jackler RK, Driscoll CLW (editions): Tumors of the
Management of Temporal Bone Malignancy
125
References
Ear and Temporal Bone. Philadelphia, Lippincott, Williams, and Wilkins;
67-83.
Moffat D.A., Grey P., Ballagh R.H. (1997): Extended temporal bone
resection for squamous cell carcinoma. Otolaryngology-Head & Neck
Surgery; 116: 617-623.
Moffat D.A., Wagstaff S.A. and Hardy D.G. (2005): The outcome of
radical surgery and postoperative radiotherapy for squamous carcinoma
of the temporal bone Laryngoscope; 115: 341-347.
Moody S.A., Hiersh B.E. and Meyers E.N. (2000): Squamous cell
carcinoma for the external auditory canal: An evaluation of a staging
system. Am. J. Otolaryngol.; 21: 582-588
Moreano E.H., Paparella M.M., Zelterman D. and Goycoolea M.V.
(1994): Prevalence of facial canal dehiscence and of persistent stapedial
artery in the human middle ear: a report of 1000 temporal bones.
Laryngoscope; 104: 309-320
Morotti R.A., Nicol K.K. and Parham D.M. (2006): An
immunohistochemical algorithm to facilitate diagnosis and subtyping of
rhabdomyosarcoma: the children’s oncology group experience, American
Journal of Surgical Pathology; 30 (8): 962-968.
Nadol J.B. and Schuknecht H.F. (1993): Surgery of the ear and
temporal bone. New York: Raven Press.
Naguib M., Aristegui M., Saleh E., Cokkeser Y., Landolfi M. and
Sanna M. (1994): Surgical anatomy of the petrous apex as it relates to
the enlarged middle cranial fossa approaches. Otolaryngology-Head &
Neck Surgery; 11: 488-493.
Nakagawa T., Kumamoto Y. and Natori Y. (2006): Squamous cell
carcinoma of the external auditory canal and middle ear: An operation
combined with preoperative chemoradiotherapy and a free surgical
margin. Otology & Neurotology; 27: 242-249
Management of Temporal Bone Malignancy
126
References
Narayan D. and Ariyan S.(2001): Surgical considerations in the
management of malignant melanoma of the ear. Plast Reconstr Surg ;
107: 20–24.
Nathu R.M., Mendenhall N.P., Almasri N.M. And Lynch J.W. (1999):
Non-Hodgkin’s lymphoma of the head and neck: a 30-year experience at
the University of Florida. Head Neck; 21(3): 247-54
Neely J.G. (1982): Anatomic considerations of the medial cuts in the
subtotal temporal bone resections. Otolaryngology-Head and Neck
Surgery; 90:641-645
Nelson E.G. and Hinojosa R. (1991): Histopathology of metastatic
temporal bone tumors. Arch Otolaryngology Head Neck Surg.; 117: 189193.
Newton W.A. Jr., Gehan E.A. and Webber B.L. (1995): Classification of
rhabdomyosarcomas and related sarcomas. Pathologic aspects and
proposal for a new classification: an intergroup rhabdomyosarcoma
study, Cancer; 76(6): 1073-1085.
Nomura Y. (1984): Otological significance of the round window.
Advances in Otorhinolaryngology; 33: 1-162.
Paaske P.B., Witten J., Schwer S. and Hansen H.S. (1987): Results in
treatment of carcinoma of the external auditory canal and middle ear.
Cancer; 56: 156-160.
Palmer J. and Snell G. (1979): Surgical treatment of extensive tumors of
the lateral face and auricular areas by radical soft tissue and subtotal
temporal bone excision with deltopectoral flap coverage. J
Otolaryngology; 8: 531.
Panigrahy A., Caruthers S.D. and Krejza J. (2000): Registration of
threedimensional MR and CT studies of the cervical spine. American
Journal of Neuroradiology; 21: 282-289.
Management of Temporal Bone Malignancy
127
References
Panosian M.S. and Roberts J.K. (1994): Plasmacytoma of the middle
ear and mastoid. Am. J. Otolaryngol.; 15: 264-267.
Parham D.M. (2001): Pathologic classification of rhabdomyosarcomas
and correlations with molecular studies, Modern Pathology; 14 (5): 506514.
Parsons H. and Lewis J.S. (1954): Subtotal resection of the temporal
bone for cancer of the ear. Cancer; 7: 956-1001
Pawlik T.M., Paulino A.F. and McGinn C.J. (2003): Cutaneous
angiosarcoma of the scalp: a multidisciplinary approach. Cancer; 98:
1716-1726.
Pensak M.L. and Willging J.P. (1994): Tumors of the temporal bone.
InJackler RK, Brackmann DE (editions): Neurotology. St. Louis, MosbyYear Book: 1049-1057.
Pensak M.L., Gleich L.L. and Gluckman J.L. (1996): Temporal bone
carcinoma: Contemporary perspectives in the skull base surgical era.
Laryngoscope; 106:1234-1237.
Perzin K.H., Gullane P. and Conley J. (1982): Adenoid cystic
carcinoma involving the external auditory canal. Cancer; 50: 2873-2883.
Pfreundner L., Schwager K.,Willner J., Baier K., Bratengeier K. and
Brunner F.X. (1999): Carcinoma of the external auditory canal and
middle ear. International Journal of Radiation Oncology, Biology &
Physics; 44: 777-788
Pfreundner L., Sschwager K.,Willner J., Baier K., Bratengeier K.,
Brunner F.X., and Flentje M. (1999): Carcinoma of the external
auditory canal and middle ear. International Journal of Radiation
Oncology, Biology and Physics; 44(4): 777-788
Pockaj B.A., Jaroszewski D.E. and DiCaudo D.J. (2003): Changing
surgical therapy for melanoma of the external ear. Annals of Surgical
Oncology; 10: 689-696.
Management of Temporal Bone Malignancy
128
References
Politzer A. (1883): A textbook of diseases of the ear, London baillier
Tindadl & Cox.
Prabhu R. , Hinerman R., Indelicato D., Morris C., Werning J.,
Mikhail Vaysberg, Amdur R., Kirwan J. and Mendenhall
W.(2009):Squamous Cell Carcinoma of the External Auditory Canal
Long-Term Clinical Outcomes Using Surgery and External-Beam
Radiotherapy. American Journal of Clinical Oncology; 32: 401-404.
Prasad S. and Janecka I. (1994): Efficacy of surgical treatments for
squamous cell carcinoma of the temporal bone: a literature review.
Otolaryngology-Head & Neck Surgery; 110: 270.
Prasad S. and Janecka I.P. (2010): Malignancies of the Temporal BoneRadical Temporal Bone Resection. Otologic surgery by Derald E.
Brackmann, Clough Shelton and Moisés A. Arriaga 3rd edition chapter 4.
Procter B. and Nager G.T. (1982): The facial canal: normal anatomy,
variations and anomalies. Annuals of Otology, Rhinology &
Laryngology; 91& 97: 33-61.
Raghu M., Moumoulidis I., Ranit D.E. and Moffat D. (2004):
Chondrosarcomas of the temporal bone: presentation and management,
The Journal of Laryngology & Otology; l (118): 551-555.
Remley K.B., Swartz J.D. and Harnsberger H.R. (1998): The external
auditory canal. In: Swartz J.D., Harnsberger H.R. editions. Imaging of
the Temporal Bone, 3rd edition. Thieme, New York, USA: 16-20.
Ries L.A., Kosary C.L. and Hankey B.F. (1999): SEER Cancer Statistics
Review, 1973—1996, National Cancer Institute, Bethesda.
Saim L., McKenna M.J. and Nadol J.B. (1996): Tubal and tympanic
openings of the peritubal cells: implications for cerebrospinal
fluidotorrhea. Am. J. Otolaryngol.; 17: 335-339.
Saleh E., Naguib M., Aristegui M., Cokkeser Y., Russo A. and Sanna
M. (1995): Surgical anatomy of the jugular foramen area. In: Mazzoni A,
Management of Temporal Bone Malignancy
129
References
Sanna M, editors. Skull base surgery update, volume 1. Amsterdam:
Kugler: 3-8.
Sanna M. (1980): Anatomy of the posterior mesotympanum. In: Zini C,
Sheehy JL, Sanna M, editors. Microsurgery of cholesteatoma of the
middle ear. Milan: Ghedini: 69-73.
Sasaki C.T. (2001): Distant metastases from ear and temporal bone
cancer. ORL: J Otorhinolaryngology & Related Specialties; 63: 250-251.
Sataloff R.T., Roberts B.R., Myers D.L. and Spiegel J.R. (1988): Total
Temporal Bone Resection, A radical but life-saving procedure.
Association of Perioperative Registered Nurses Journal; 48(5): 932-948
Sbeity S., Abella A., Arcand P., Quintal M.C. and Saliba I. (2007):
Temporal bone rhabdomyosarcoma in children. International J of
Pediatric Otorhinolaryngology; 71(5): 807-814
Sekhar L., Pomeranz S. and Janecka I. (1992): Temporal bone
neoplasms: a report on 20 surgically treated cases. J Neurosurgery; 76:
578.
Shaffer K.A., Haughton V.M. and Wilson C.R. (1980): High resolution
computed tomography of the temporal bone. Radiology; 134: 409-414.
Shih L. and Crabtree J.A. (1990): Carcinoma of the external auditory
canal: An update. Laryngoscope; 100: 1215-1218.
Shockley W. and Stucker F. (1987): Squamous cell carcinoma of the
external ear: a review of 75 cases. Arch. Otolaryngol Head Neck Surg.;
97: 308.
Skedros D.G., Cass S.P. and Hirsch B.E. (1993): Beta-2 transferrin
assay in clinical management of cerebral spinal fluid and perilymphatic
fluid leak. J Otolaryngology; 22: 341-344
Management of Temporal Bone Malignancy
130
References
Soh K.B., Tan H.K. and Sinniah R. (1996): Mucoepidermoid carcinoma
of the middle ear-a case report. Journal of Laryngology and Otology 110,
p: 249-251.
Spiegel E.A., Wycis H.T. and Marks M. (1947): Stereotactic apparatus
for operations on the human brain. Science; 106: 349-350
Spreer J., Krahe T., Jung G. and Lackner K. (1995): Spiral versus
conventional CT in routine examinations of the neck. J of Computer
Assisted Tomography; 19: 905-910.
Swartz J.D. (1986): Imaging of the Temporal Bone. Thieme, New York.
Swartz J.D. and Harnsberger H.R. (1998): The middle ear and mastoid.
In: Swartz J.D. and Harnsberger H.R. editions. Imaging of the Temporal
Bone, 3rd edition. Thieme, New York, USA: 47-60.
Takahashi Y., Nakao Y., Hayashi T., T.K. and Nasus A. (2002):
Mesenchymal chondrosarocoma of the temporal bone. Larynx; 29: 371374
Taylor S. (1982): The petrous temporal bone (including the
cerebellopontine angle). Radiologic Clinics of North America; 20: 67-86.
Testa J.R.G., Fukuda Y., Kowalski L.P. (1997): Prognostic factors in
carcinoma of the external auditory canal. Arch. Otolaryngol Head Neck
Surg.; 123: 720-724.
Tien R.D. (1992): Fat suppression MR imaging in neuroradiology:
techniques and clinical application. American Journal of Roentgenology;
158: 369-379.
Tien R.D., Hesselink J.R. and Chu P.K. (1991): Improved detection and
delineation of head and neck lesions with fat suppression spinecho MR
imaging. American Journal of Neuroradiology; 12: 19-24.
Management of Temporal Bone Malignancy
131
References
Tzagaroulakis A., Pasxalidis J. and Papadimitriou N. (2003) :
Recurrent ceruminouss adenocarcinoma of the external auditory canal.
ORL: J Otorhinolaryngology & Related Specialties; 65: 300-302.
Vantuchova Y. and Curik R. (2006): Histological types of basal cell
carcinoma. Scripta Medica (Brno):79(5-6): 261-270
Vrtiska T., Fletcher J. and McCollough C. (2005): State-of-the-art
imaging with 64-channel multidetector CT angiography. Perspectives in
Vascular Surgery and Endovascular Therapy; 17(1): 3-10.
Wada T., Fujisaki T., Satoh H. and Takahashi S. (2006):
Endolymphatic sac tumor located around semicircular canals. Auris
Nasus Larynx; 33: 173-177
Wagenfeld D.J.H., Keane T., van Nostrand A.W.P. and Bryce D.P.
(1980): Primary carcinoma involving the temporal bone: analysis of
twenty-five cases. Laryngoscope; 90: 912-919.
Wang C.C. (1975): Radiation therapy in the management of carcinoma
of the external auditory canal, middle ear, or mastoid. Radiology; 116:
713-715.
Wiatrak B.J. and Pensak M.L. (1989): Rhabdomyosarcoma of the ear
and temporal bone. Laryngoscope; 99: 1188-1192.
Woodruff K.H., Lyamn J.T. and Lawrence J.H. (1984): Delayed
sequelae of pituitary irradiation. Human Pathology; 15: 48-54.
Yagisawa M., Ishitoya J., Tsukuda M. and Sakagami M. (2007):
Chondrosarcoma of the temporal bone. Auris Nasus Larynx; 34: 527531.
Yeung P., Bridger A., Smee R., Baldwin M. and Bridger G.P. (2001):
Malignancies of the external auditory canal and temporal bone: A review.
ANZ J. of Surgery; 72: 114-120.
Management of Temporal Bone Malignancy
132
References
Yeung P., Bridger A., Smee R., Baldwin M. and Bridger G.P. (2002):
Malignancies of the external auditory canal and Temporal bone: a review.
ANZ J. Surgery; 72: 114-120
Yilmaz I., Bolat F., Demirhan B., Aydin V. and Levent N. (2008):
Endolymphatic sac papillary tumor: A case report and review. Auris
Nasus Larynx; 35(2): 276-281
Management of Temporal Bone Malignancy
133
‫الملخص العربي‬
‫الملخص العربي‬
‫اٌعظُ ا ٌصذغ‪ ٛ٘ ٟ‬عظُ ِعمذ اٌزشو‪١‬ت ‪٠‬زى‪ ِٓ ْٛ‬عذح أخزاء ‪٠ٚ‬حز‪ ٞٛ‬عٍ‪ ٝ‬أعضبء ٘بِخ خذا ِٕ‪ٙ‬ب‬
‫األرْ اٌ‪ٛ‬سط‪ٚ ٝ‬االرْ اٌذاخٍ‪١‬خ اٌّسؤ‪ٌٚ‬خ عٓ اٌسّع ‪ٚ‬االرزاْ ف‪ ٟ‬االٔسبْ‪ .‬وّب أٔٗ ‪ٛ٠‬خذ ثد‪ٛ‬اس أخزاء‬
‫٘بِخ خذا ِٕ‪ٙ‬ب اٌفص اٌصذغ‪ٌٍّ ٟ‬خ ‪ٚ‬اٌشش‪٠‬بْ اٌسجبر‪ ٟ‬اٌذاخٍ‪. ٟ‬‬
‫‪ٚ‬فمب ٌٍ‪١ٙ‬بوً إٌس‪١‬د‪١‬خ اٌّخزٍفخ ف‪ ٟ‬اٌعظُ اٌصذغ‪ٕ٘ ٟ‬بن اٌعذ‪٠‬ذ ِٓ األ‪ٚ‬ساَ اٌز‪ّ٠ ٟ‬ىٓ أْ رٕشأ‬
‫ِٕ‪ٙ‬ب‪ٚ.‬رمسُ ٘زٖ األ‪ٚ‬ساَ بالنسبة لمنشئها ‪،‬إِب أْ رٕشأ ِٓ األر ن الخارجية بما فيها صوان األذن ‪ٚ‬‬
‫اٌمٕبح اٌسّع‪١‬خ أ‪ ٚ‬األرْ اٌ‪ٛ‬سط‪ٚ ٝ‬اٌذاخٍ‪١‬خ‪.‬‬
‫ِٓ ٘زٖ األ‪ٚ‬ساَ ‪ :‬األ‪ٚ‬ساَ اٌظب٘ش‪٠‬خ ِثً سشطبْ اٌخال‪٠‬ب اٌمبعذ‪٠‬خ ‪ٚ‬اٌسشطبٔبد اٌغذ‪٠‬خ ‪ٚ‬اٌسشطبٔبد‬
‫اٌحششف‪١‬خ‪ٕ٘ٚ .‬بن اٌسشطبٔبد اٌٍحّ‪١‬خ اٌز‪ ٟ‬رظ‪ٙ‬ش ِٓ األ‪ٚ‬ع‪١‬خ اٌذِ‪٠ٛ‬خ ‪ٚ‬اٌخال‪٠‬ب اٌعضٍ‪١‬خ اٌّ‪ٛ‬خ‪ٛ‬دح‬
‫ثعظّخ اٌصذغ ‪.‬‬
‫‪ٕ٘ٚ‬بن أ‪ٚ‬ساَ لذ رٕشأ ِٓ األعضبء اٌّزبخّخ ٌعظّخ اٌصذغ ‪ٚ‬رٕزشش إٌ‪ٙ١‬ب عٓ طش‪٠‬ك اإلٔزشبس‬
‫اٌّجبشش‪.‬أ‪ ٚ‬لذ رٕشأ ِٓ أعضبء ثع‪١‬ذح عٓ عظّخ اٌصذغ ‪ٚ‬رصً اٌ‪ٙ١‬ب عٓ طش‪٠‬ك اٌذَ‪.‬‬
‫ٌأل‪ٚ‬ساَ اٌخج‪١‬ثخ ٌعظبَ اٌصذغ اٌمذسح عٍ‪ ٝ‬ا‪ٔ٢‬زشبس ِجبششح إٌ‪ ٝ‬األٔسدخ اٌّح‪١‬طخ ث‪ٙ‬ب ِثً اٌغذح‬
‫إٌىف‪١‬خ ِٓ خالي شم‪ٛ‬ق سبٔز‪ٛ‬س‪ٚ ٟٕ٠‬وزٌه إٌ‪ ٝ‬اٌفص اٌصذغ‪ٌٍّ ٟ‬خ‪ٚ.‬رٕزشش ف‪ ٝ‬اٌعّك إٌ‪ِ ٝ‬حز‪٠ٛ‬بد‬
‫األرْ اٌ‪ٛ‬سط‪ِ ٝ‬ثً عصت اٌ‪ٛ‬خٗ ثُ إٌ‪ ٝ‬األرْ اٌذاخٍ‪١‬خ حز‪ ٝ‬رصً إٌ‪ ٝ‬اٌشش‪٠‬بْ اٌسجبر‪ ٟ‬اٌذاخٍ‪.ٟ‬‬
‫‪ٚ‬ثصفخ عبِخ ‪ ،‬يأل‪ٚ‬ساَ اٌخج‪١‬ثخ ٌعظبَ اٌصذغ ِعذي ِٕخفط ٌالٔزشبس ٌٍغذد اٌٍّفب‪٠ٚ‬خ ‪ٚ‬اٌذَ ‪ٌٚ‬ىٓ إرا‬
‫حذس رٌه رى‪ ْٛ‬إٌزبئح اٌّز‪ٛ‬لعخ ٌٍعالج س‪١‬ئخ ‪.‬‬
‫‪٠‬زشا‪ٚ‬ذ سٓ األصبثخ ةاأل‪ٚ‬ساَ اٌخج‪١‬ثخ ف‪ ٟ‬عظبَ اٌصذغ ِٓ سز‪ ٓ١‬سٕخ فأوثش ِبعذا ف‪ ٟ‬ثعط األ‪ٚ‬ساَ‬
‫اٌٍحّ‪١‬خ اٌخج‪١‬ثخ ‪ٕ٠‬خفط ِز‪ٛ‬سظ اٌعّش اٌ‪ ٝ‬اٌفئبد األصغش سٕب ‪.‬‬
‫عبدح ‪٠‬ظ‪ٙ‬ش اٌّشض عٍ‪ ٝ‬شىً اٌز‪ٙ‬بة صذ‪٠‬ذ‪ِ ٞ‬زِٓ ثبألرْ ال‪٠‬سزد‪١‬ت ٌٍعالخبد اٌذ‪ٚ‬ائ‪١‬خ أ‪ ٚ‬عٍ‪ٝ‬‬
‫شىً سٍ‪ٍ١‬خ خبسخخ ِٓ األرْ ‪ٚ‬اٌز‪ ٟ‬رؤد‪ ٞ‬اٌ‪ٔ ٝ‬ز‪٠‬ف عٕذ ٌّس‪ٙ‬ب‪ٚ .‬لذ ‪٠‬ظ‪ٙ‬ش اٌّشض ثبعشاض أزشبس‬
‫اٌ‪ٛ‬سَ ِثً شًٍ اٌعصت اٌّخ‪ ٟ‬اٌسبثع أ‪ٚ ٚ‬سَ ثبٌغذح إٌىف‪١‬خ ا‪ ٚ‬اٌعمذ اٌٍ‪ّ١‬فب‪٠ٚ‬خ اٌعٕم‪١‬خ‪.‬‬
‫‪1‬‬
‫عالج األورام الخبيثة لعظمة الصدغ‬
‫الملخص العربي‬
‫ٌٍحص‪ٛ‬ي عٍ‪ ٝ‬اٌزشخ‪١‬ص اٌذل‪١‬ك ٌأل‪ٚ‬ساَ اٌخج‪١‬ثخ ٌعظبَ اٌصذغ ‪٠‬دت أْ رؤخز ع‪ٕ١‬خ ِٓ اٌ‪ٛ‬سَ وتحلل‬
‫ثبث‪ٌٛٛ‬خ‪١‬ب‪ .‬وّب أْ األشعخ اٌّمطع‪١‬خ ‪ٚ‬اٌشٔ‪ ٓ١‬اٌّغٕبط‪١‬س‪ٍ٠ ٟ‬عت د‪ٚ‬س ٖ‬
‫اَ خذا ف‪ ٟ‬رشخ‪١‬ص اٌ‪ٛ‬سَ‬
‫ٌّعشفخ ِذ‪ ٜ‬أزشبسٖ ٌألٔسدخ اٌّدب‪ٚ‬سح ‪ٚ‬رٌه ٌزحذ‪٠‬ذ أٔست اٌطشق اٌعالخ‪١‬خ س‪ ٛ‬اء وبٔذ عٓ طش‪٠‬ك‬
‫اٌعالج اٌدشاح‪ ٟ‬أ‪ ٚ‬اإلشعبع‪.ٟ‬‬
‫عالج األورام الخبيثة لعظمة الصدغ يمكن أن يكون عن طريق الجراحة أو اإلشعاع أو مزيج من‬
‫االثنين معا‪.‬‬
‫بالنسبة لدور العالج الكيميائي فإنه مقصور فقط على بعض األورام اللحمية الخبيثة وكذلك في عالج‬
‫االنبثاثات البعيدة من الورم‪.‬‬
‫برنامج العالج الجراحي لألورام الخبيثة لعظمة الصدغ يعتمد أساسا على مدى امتداد الورم داخل‬
‫العظمة وخارجها‪ .‬وبالتالي يمكن أن يكون في صورة استئصال جزئي أو شبه كلي أو استئصال‬
‫كلي لعظمة الصدغ‪.‬‬
‫بالنسبة للعالج االشعاعي إما أن يكون هو أساس العالج وذلك في حالة األورام الصغيرة في حجمها‬
‫والمحدودة في إمتدادها‪ .‬أو يكون مكمال للعالج الجراحي في حالة األورام االكبر حجما و األكثر‬
‫امتدادا‪.‬‬
‫من الصعب تحديد تكهن كافي وصحيح في عالج االورام الخبيثة لعظمة الصدغ وذلك ألسباب عدة‬
‫منها ندرة هذه األورام وعدم توفر احصائيات ودراسات دقيقة لهذه الحاالت وكذلك لعدم وجود نظام‬
‫عالجي متفق عليه عالميا‪.‬‬
‫بشكل عام يكون التكهن سيئا اذا وجد أن الورم امتد الى أعضاء هامة مثل الفص الصدغي للمخ‬
‫والشريان السباتي الداخلي‪ .‬ويكون جيدا اذا تم اكتشاف الورم في مرحلة مبكرة وتم استئصاله كليا‬
‫بالجراحة وتم اعطاء العالج اإلشعاعي المكمل له‪.‬‬
‫‪2‬‬
‫عالج األورام الخبيثة لعظمة الصدغ‬
‫عالج األورام الخبيثة لعظمة الصدغ‬
‫رسالة مقدمة من الطبيب‬
‫أحمد فتحي محمد الدحن‬
‫توطئة للحصول على درجة الماجيستير‬
‫في األذن واألنف والحنجرة‬
‫تحت اشراف‬
‫أ‪.‬د‪ / .‬اسماعيل زھدي‬
‫أستاذ األذن و األنف و الحنجرة‬
‫كلية الطب‬
‫جامعة القاھرة‬
‫أ‪.‬د‪ / .‬لؤي الشرقاوي‬
‫أستاذ األذن و األنف و الحنجرة‬
‫كلية الطب‬
‫جامعة القاھرة‬
‫د‪ /‬باھر عاشور‬
‫مدرس األذن و األنف و الحنجرة‬
‫كلية الطب‬
‫جامعة القاھرة‬
‫‪٢٠١٠‬‬