Download odontogenic tumors 2

Dr. Saleem Shaikh
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Also known as Pindborg tumour.
The cell of origin is unknown but some have suggested that
it arises from the cells in the stratum intermedium layer of
the enamel organ in tooth development.
Clinical features: Most patients with this lesion are
asymptomatic and are aware only of a painless swelling.
Rarely it may develop symptoms.
More commonly seen in the mandibular third molar
ramus region.
Radiographic feature: It may appear as a well-circumscribed
unilocular radiolucent area, while in other cases there may
appear to be a combined pattern of radiolucency and
radiopacity.
Scattered flecks of calcification throughout the radiolucency
have given rise to the descriptive term of a “driven snow”
appearance.
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Histologic features: tumor is composed of polyhedral
epithelial cells, sometimes closely packed in large sheets,
with a finely granular eosinophilic cytoplasm, and
intercellular bridges are often prominent. The nuclei are
frequently pleomorphic, with giant nuclei.
One of the characteristic microscopic features of this tumor
is the presence of a homogeneous, eosinophilic substance
which has been variously interpreted as amyloid, it stains
metachromatically with crystal violet, positively with Congo
red, and fluoresces under ultraviolet light with thioflavin T.
these stains may be used to identify the tumor.
Another characteristic feature of the Pindborg tumor is the
presence of calcification, sometimes in large amounts, and
often in the form of Liesegang rings.
Treatment: surgical excision
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It is a benign tumor named because of it resemblance to
glandular tumors. It has very less growth potential and has
been categorized as a hamartomatous malformation.
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Clinical features: generally seen as asymptomatic swelling in
patients who are young – less than 20 yrs.
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occurs more frequently in the anterior part of the maxilla
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Most of the tumors are associated with an unerupted tooth.
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Radiographic features: AOTs present as a well-demarcated,
almost always unilocular radiolucency that generally exhibits a
smooth corticated (and sometimes sclerotic) border.
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Most lesions are pericoronal or juxtacoronal to the unerupted
tooth but the radiolucency may extend apically beyond the
cemento-enamel junction on at least one side of the root.
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Histologic features: tumor is made up of a multinodular
proliferation of spindle, cuboidal, and columnar cells in a
variety of patterns comprising of scattered ductlike
structures (whorled pattern)
the most distinctive microscopic feature of AOT is varying
numbers of ductlike structures with lumina of varying size
that are lined by a single layer of cuboidal to columnar
epithelial cells.
microcyst lumina frequently are lined by an eosinophilic rim
of varying thickness (the so-called ‘‘hyaline ring’’).
Treatment: conservative excision.
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It is a rare tumor which has been recently recognized,
Most important aspect of this tumor is its resemblance to
acanthomoatous ameloblastoma and squamous cell
carcinoma.
The lesions were often asymptomatic but presenting
manifestations included mobility of involved teeth.
It is composed entirely of islands of mature squamous
epithelium without a peripheral palisaded or polarized
columnar layer.
the islands in squamous odontogenic tumor are well
defined, and the cells lack variation in cell size, shape and
nuclear staining and mitotic figures that are
characteristically seen in squamous cell carcinoma.
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It is a relatively uncommon neoplasm of odontogenic origin
which is characterized by the simultaneous proliferation of
both epithelial and mesenchymal tissue without formation
of enamel or dentin.
Clinical Features: This tumor exhibits somewhat slower
clinical growth than the simple ameloblastoma and does not
tend to infiltrate between trabeculae of bone. Instead it
enlarges by gradual expansion so that the periphery of the
lesion often remains smooth. Usually discovered
accidentally during roentgenographic examination. Pain,
tenderness or mild swelling of the jaw may be seen.
Radiographic features: manifested as a unilocular or
multilocular, radiolucent lesion which has a rather smooth
outline, often with a sclerotic border.
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Histologic Features: The ectodermal portion consists of
scattered islands of epithelial cells in a variety of patterns,
including rosettes, long finger-like strands, nest and cords.
These epithelial cells are usually of a cuboidal or columnar
type and bear close resemblance to primitive odontogenic
epithelium
The mesenchymal component is made up of a primitive
connective tissue that in some cases shows closely
intertwining fibrils interspersed by large connective tissue
cells closely resembling those of the dental papilla.
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The term “odontoma,” by definition alone, refers to any
tumor of odontogenic origin.
a growth in which both the epithelial and the mesenchymal
cells exhibit complete differentiation, functional
ameloblasts and odontoblasts form enamel and dentin
This enamel and dentin are usually laid down in an
abnormal pattern
It has limited growth potential hence considered as a
hamartomatous malformation rather than a neoplasm
This lesion is composed of more than one type of tissue and,
for this reason, has been called a composite odontoma.
Two types compound composite odontomas - when there is at least
superficial anatomic similarity to normal teeth.
complex composite odontoma - when the calcified dental
tissues are simply an irregular mass bearing no morphologic
similarity to teeth.
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Clinical features: The odontoma may be discovered at any
age in any location of this dental arch.
The compound odontoma had predilection in this study for
the anterior maxilla
complex odontomas had a predilection for the posterior
mandible
Most odontomas are asymptomatic, although occasionally
signs and symptoms relating to their presence do occur.
These generally consist of unerupted or impacted teeth,
retained deciduous teeth and swelling.
Radiographic features: They are often situated between the
roots of teeth and appear as an irregular mass of calcified
material surrounded by a narrow radiolucent band
resembling a tooth or the odontoma may appear also as a
calcified mass overlying the crown of an unerupted or
impacted tooth.
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Histologic Features: normal-appearing enamel or
enamel matrix, dentin, pulp tissue and cementum which
may or may not exhibit a normal relation to one another.
One additional interesting feature is the presence of “ghost”
cells in odontomas. These are the same cells described in the
calcifying odontogenic cyst
Treatment and Prognosis: The treatment of the
odontoma is surgical removal, and there is no expectancy of
recurrence.
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Odontogenic malignancies are very uncommon tumours.
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METASTASIZING AMELOBLASTOMA: The term
‘‘metastasizing ameloblastoma’’ is used to describe a tumor
that shows histologic features of classic ameloblastoma in
the gingiva or jaw and has metastatic deposits elsewhere.
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AMELOBLASTIC CARCINOMA: Ameloblastic
carcinoma is a malignant epithelial proliferation that is
associated with an ameloblastoma. Demonstrates greater
cytologic atypia and mitotic activity than ameloblastoma