Download PARAGANGLIOMAS OF THE HEAD AND NECK : review

PARAGANGLIOMAS OF THE
HEAD AND NECK :
review of imaging findings.
AB Valentín Martín
E Fandiño Benito
A Enríquez Puga
PM Aguilar Ángulo
MJ Adán Martín
A Pérez Martínez
Servicio de Radiodiagnóstico
Hospital Virgen de la Salud,
Toledo ESPAÑA (SPAIN)
Learning Objectives:

To review the imaging characteristics on
different imaging modalities of paragangliomas
of the head and neck, diagnosed in our hospital
in the last 5 years.
Background:


Paragangliomas are generally benign, slow growing
tumors arising from widely distributed paraganglionic
tissue originating from the neural crest.
Paraganglia are distributed in the head and neck near
nerves and vessels.

They are small structures that have been shown to have a
chemoreceptor role by modulating respiratory and
cardiovascular function in response to fluctuations in arterial
pH, oxygen and carbon dioxide tension, and other chemical
alterations.

Paragangliomas are uncommon neoplasms, accounting for 0.6%
of all the head and neck region tumors.

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The four most commun sites are the carotid body at the common carotid
artery bifurcation, the jugular foramen, along the vagus nerve and in the
middle ear.
Usually they are sporadic cases (5% multicentric).
There are also cases of familial presentation. The inheritance
pattern for familial paragangliomas is autosomal dominant. (In
this case, the tendency for multicentricity is much higher - about
40-50%).

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They usually grow slowly and remain undetected
for years.
The presentation of head and neck is rare and
occur mainly in four areas:
the carotid body at the common carotid artery
(CCA)
 the jugular foramen
 along the vagus nerve
 within the middle ear

Imaging Findings:

We review paragangliomas of head and neck, diagnosed in our
hospital in the last 5 years (2003-2008). We analyze the
characteristic findings on radiologic images ultrasound,
computed tomographic (CT), magnetic resonance (MR) and/or
angiographic studies, according to the cases.

In the 32 patients were diagnosed by radiological imaging 34
paragangliomas that were distributed in this way: 18 (53%)
carotid body; 11 jugulars(32%); 3 (8.8%)tympanic and 2
(5.8%)vagal paragangliomas. Two patients showed a second

paraganglioma carotid contralateral.
83,2% were females and average age was 52,7 years.



In our experience, the most common sites were the
carotid body (53%) and glomus jugular (32%). They
present as slow-growing tumors, with few symptoms,
and imaging tests as well defined and hypervascular
masses.
The relationship with the vessels is a key factor in the
differential diagnosis.
We show the best examples of each subtype illustrated
and we discussed the main findings.
1- Carotid paragangliomas

The carotid body is located within or outside the
adventitial layer of the CCA, at the bifurcation, usually
along the posteromedial wall.

It can also be located along each branch of the CCA: the
external carotid artery (ECA) or the internal carotid artery
(ICA).

PARAGANGLIOMA CHARACTERISTICS:

They usually present as a slow growing painless neck mass
located at the anterior border of the sternocleidomastoid
muscle just lateral to the tip of the hyoid bone.


The diagnosis of a carotid paraganglioma is made by finding a
mass arising from the carotid bifurcation which displaces the
external and internal carotid arteries.


The mass has typically been present for several years.
Splaying of the common carotid bifurcation is very suggestive of a
carotid body tumor.
In his progression, it can affect the lower cranial nerves and
the pharynx.

Even may also extend to the skull base and invade the cranial cavity.
Imaging findings:
Ultrasound:
a solid mass (m), rounded or oval,
well defined, heterogeneously
hypoechoic in the lateral neck. It
wides the carotid bifurcation.


ICA
ECA
m
CT:


Without contrast enhanced: a well-defined soft tissue mass
within the carotid space infrahyoid, on the bifurcation of
CCA. This mass splays the ECA from the ICA, without
narrowing the caliber of the vessels.
With enhanced contrast: homogeneous and intense enhanced
mass


The preferred imaging choice for carotid body tumors is MRI and MRA. They
provide good insight into the vascularization of the tumor and the origin and
contribution of the several branches of the external carotid arteries.
MRI: A well-defined mass with

“Appearance of salt and pepper”:

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Salt: high-signal areas within the tumor, secondary to subacute hemorrhages or slow
flow zones.
Pepper: areas of low intensity (signal voids) for fast flow in feeding arteries
T1-weighted images: hypointense signal intensity.
T2- weighted images : high signal intensity.
Postcontrast Т1-weighted images: intense and
homogeneous enhancement.

MR Angiography (MRA):


separation between the ICA and ECA, but not see the tumor
capillary bed
Angiography:

a hypervascular mass with enlarged feeding arteries (throught
ascending pharyngeal artery, a branch of the ACE), after
intense tumor blush and early venous drainage.
m
Carotid body tumor in a 36year-old woman with a slowly
growing, right-sided neck mass
for several months and recent
onset of local inflammatory
symptoms, and right upper
extremity paresthesias.
m
Carotid body tumor in a 43year-old woman discovered
incidentally.
m
Carotid body tumor in a 48year-old man with a slowly
growing, right-sided neck mass
for several years.
•Contrast-enhanced axial CT image demostrates
an intensely enhancing right carotid space mass (m)
that splays the ECA (yellow arrow) from de ICA
(blue arrow).
Contrast-enhanced coronal CT image
Contrast-enhanced sagital CT image
VR
m
m
m
CCA
CCA
CCA
MIP
up
Contrast-enhanced axial CT image
m
down
CCA
IYV
Carotid body
tumor in a 32year-old
woman with
with a
asintomatic
slowly
growing,
right-sided
neck mass.
Axial CT
A 65-year-old woman with traumatic brain injury.
Asymptomatic palpable mass at the angle of the jaw.
•Axial CT without contrast enhanced image shows a well-defined soft
tissue mass within the carotid space.
m
•Sagital T1-weighted MR image demostrates a right-sided neck mass (m)
that is isointense to muscle at the level of the common carotid bifurcation.
The ECA (yellow arrow) is splayed from the ICA (blue arrow).
•Postcontrast Т1-weighted image shows shows intense tumor enhancement,
Sagital T1-weighted MR image
Postgadolinium Sagital T1-weighted MR image
MR Angiography
m
m
m
The same patient before
Lateral angiographic view obtained after a
right CCA injection
Frontal angiographic view obtained after a
right CCA injection
m
CCA
•Angiographic images show splaying of
the ECA from the ICA by a hipervscular
mass that extends to the bifurcation.

m
m
A high percentage of carotid
body paragangliomas occur
in patients with chronic
obstructive pulmonary
disease (COPD) and in
populations living at high
altitudes (eg.Perú, Mexico).


A 70-year-old man with lung neoplasm. In
control CT is discovered a bilateral carotid
paraganglioma.(m).
It is believed to be due to chronic
hypoxia in combination with
genetic factors.
Paragangliomas may be
multi-centric in origin, and
may manifest as unilateral or
bilateral lesions.

Bilateral carotid body tumors:

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5% of sporadic cases
35% of familial cases
2-Glomus yugulare tumor

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It is the most common tumor of the jugular fossa with
intracranial extension.
They arise within the jugular foramen (either from the
jugular bulb, Jacobson nerve or Arnold nerve).
The
patterns of spread of the yugular paraganglioma follow
the paths of least resistance, including mastoid air cell tracts,
vascular channels, eustachian tube (tumor jugulotympanicum)
and neural foramina.
Progressive
growth of the tumor produces the characteristic
moth-eaten pattern of erosion of the temporal bone.
Imaging findings:
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CT:
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A soft tissue mass , typically located just under the skull base, at the bulb
of the external jugular vein.
With intense contrast enhancement
When the tumor is small, the jugular fossa is enlarged and its margins are
irregular.
Progressive growth of the tumor produces the moth-eaten pattern of
erosion of the jugular foramen and destruction of the adjacent bones.
The tumor spreads
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superiorly to hipotímpano, mesotympanum, sinus tympani and ossicular chain.
Inferiorly to internal jugular vein (IYV) and infratemporal fossa
Laterally to facial nerve canal and the facial nerve.
MRI:
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T1-weighted MR image: A soft tissue mass in a enlarged jugular bulb
fossa with “Appearance of salt and pepper”.
T2-weighted MR image: a hyperintense mass.
Postgadolinium T1-weighted MR image : intense contrast enhancement
m
A 60 year-old woman with vertigo and hearing loss.
Contrast-enhanced axial CT image demostrates a soft tissue mass (m)with intense contrast
enhancement and an irregularly marginated, destructive lesion centered in the right jugular foramen
A 56 year-old woman.
Axial and coronal CT images demostrate a soft tissue mass (red arrow) in the right
jugular bulb region.
With intense contrast enhancement and destructive bone lesion.
Contrast-enhanced, axial CT
Contrast-enhanced, coronal CT
3- Timpanic glomus.

The temporal bone glomus tissue is located at three points situated close to
the nerve of Jacobson (tympanic branch of IX) and the nerve of Arnold
(auricular branch of X).

Glomus tympanicum is the most common primary neoplasm of
the middle ear and the second most common tumour of the
temporal bone.
It is located in the mucosa of the cochlear promontory along
tympani nerve of Jacobson.
These tumors generally are limited to the middle ear, although
they may subsequently be extended to the mastoid cells.

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Imaging findings:

CT:
a small soft tissue mass abutting the promontory of
the middle ear and confined to the tympanic cavity.
 There may be displacement of ossicles or bony
erosion of the tympanic cavity.
 With intense contrast enhancement

•A 76 year-old with conductive hearing loss and pulsatile tinnitus.
-During physical exam we noticed a red-wine-color lesion on the posteroinferior quadrant of the left tympanic membrane.
-On CT scan we observed a soft tissue mass (red arrow) occupying part of
the tympanic cavity, overlapping the promontory (p)
p
p
4-Vagal paraganglioma
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Vagal paragangliomas are rare tumors that develop in
the retrostyloid compartment of the parapharyngeal
space.
They arise from an island of paraganglion tissue derived
from the neural crest that is located on the vagus nerve.

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The vagal paraganglioma most commonly arises from glomus tissue rest
located within the inferior ganglion (ganglion plexiform).
It appears as a fusiform lesion, located below the base
of the skull near the jugular foramen.
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It compresses the IJV.
The mass desplaces both the carotid vessels anterior-medially.
It pushes the lateral wall of the pharynx medially.
Minimum destruction of the skull base
Imaging findings:
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CT:
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This tumor appears similar to the carotid body paraganglioma with some
exceptions:
 Moves both the vessels (ECA and ICA) anteromedially , separating
these from the internal jugular vein.
 2 /3 of them extend to the suprahyoid carotid space.
 The center of mass is about 2 cm below the base of the skull.
MRI-T1 W:
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“Appearance of salt and pepper” with flow voids, indicating its
hypervascular nature.
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VR -MIP
A 39year-old male with a a painless lump
in his left neck of 1 years duration.
This tumor (m) displaces both the vessels
(ECA and ICA) (pink arrows)
anteromedially , separating these from the
internal jugular vein (blue arrow).
m
Contrast-enhanced, axial CT
m
m
m
m
Axial CT without contrast
m
styloid process
Contrast-enhanced, axial CT
A 85 year-old woman operated from squamous cell carcinoma in the
submandibular gland, with a lump on left carotid space just caudal to the
jugular foramen. The mass is lateral to the ICA (red arrow) and
anteromedial to the IYV (blue arrow).
styloid process
Conclusion:

Paragangliomas of head and neck are
uncommon tumors. They show characteristic
imaging findings. Their knowledge allows to
realize a very trustworthy diagnosis.
Bibliography :
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Archana B. Rao, Kelly K. Koeller, and Carol F. Adair.
Paragangliomas of the Head and Neck: Radiologic-Pathologic
Correlation. Radiographics November 1999; 19:1605-1632.
K S Caldemeyer, V P Mathews, B Azzarelli, and R R Smith. The
jugular foramen: a review of anatomy, masses, and imaging
characteristics. Radiographics September 1997; 17:1123-1139
Jane L. Weissman Glomus Vagale Tumor. Radiology April 2000;
215:237-242
Jane L. Weissman and Barry E. Hirsch Imaging of Tinnitus: A
Review. Radiology August 2000; 216:342-349