odontogenic tumor 1 ; AOT , CEOT , ameloblastoma , ameloblastic fibroma ( describing histopathology , radiographically with treatment of each disease ) l Oral pathology MCQs for dental students
Tumor of Odontogenic Tissue Origin
ADENOMATOID ODONTOGENIC TUMOR
Is rare benign, non invasive slowly progressive, odontogenic
tumor arising from enamel organ and dental lamina.
The tumor is prevalent in young age group and has more predilection
for female.
The most common location is anterior maxillae.
Tumor is associated with an unerupted tooth.
There are three variants of AOT: follicular,
extrafollicular, and peripheral.
The follicular type is a central intrabony lesion associated
with an unerupted tooth, which accounts majority of all adenomatoid odontogenic
tumors cases.
The extrafollicular type is
also an intra-osseous lesion, but unrelated to an unerupted tooth. The
peripheral type is a rare form that arises in the gingival tissue.
Radiologically tumor appears as well defined radiolucency
adjacent to an unerupted tooth. Flecks of radioopacitis may be scattered
within the radiolucency in a “snowflake” or “salt and pepper” pattern.
It should be differentially diagnosed from a dentigerous
cyst and the main difference is that the radiolucency in case of AOT extends
apically beyond the cementoenamel junction.
Treatment is Enucleation
AMELOBLASTIC FIBROMA
Is a a rare mixed benign odontogenic tumor consisting of
both epithelial and mesenchymal neoplastic component without the formation of
hard tooth structure.
The tumor is most prevalent in first and second decade of
life.
Ameloblastic fibroma originate from the enamel organ.
Tumor is mostly located in mandible.
Microscopically, Tumor are composed of young basophilic fibromyxoid
tissue. There are islands, cords and strands of ovoid, cuboidal and
occasionally columnar epithelium. There is no evidence of mineralization.
Radiologically ameloblastic fibroma is described as a small
unilocular radiolucency to a large multilocular lesion.
Treatment is the surgical excision.
AMELOBLASTIC FIBRO-ODONTOMA
Is an extremely rare odontogenic lesion. It appears most
often before age 20 years and has a slight predilection for the premolar area
in either jaw.
Ameloblastic fibro odontoma appears as a well demarcated
radiolucency with a large central opacity.
Treatment is the surgical excision.
AMELOBLASTOMA
Is a benign aggressive tumor of odontogenic epithelial
tissue origin.
The tumor has a predilection for the mandible and primarily
occurs in the molar and ramus region. Tumor is slow growing, but is more
persistent.
The lesion has a tendency to expand the bony cortices
because slow growth rate of the lesion allows time for periosteum to develop
thin shell of bone ahead of the expanding lesion. This shell of bone cracks
when palpated and this phenomenon is referred to as "Egg Shell Cracking”
or crepitus.
Tumor can cause marked deformity and facial asymmetry.
It is often seen in association with unerupted third molar
teeth.
There are three main clinical subtypes of
ameloblastoma: unicystic, multicystic, peripheral.
The peripheral subtype composes
2% of all ameloblastomas.
Unicystic ameloblastomas
represent 6% of the cases.
The six different histopathological variants of
ameloblastoma are desmoplastic, granular cell, basal cell, plexiform,
follicular, and acanthomatous. One-third of ameloblastomas are plexiform,
one-third are follicular.
Acanthomatous form is more common in older patients.
Ameloblastoma does not have a capsule. The neoplastic component is purely
epithelial. The lesion may have a reactive connective tissue component that is
not neoplastic.
Radiographically, the tumor appear as unilocular or
mutilocular radiolucency with the sclerotic, smooth, and even border.
Treatment is the surgical resection. Tumors are rarely
malignant. Recurrences are common
CALIFYING EPITHELIAL ODONTOGENIC TUMOR
OR PINDBORG TUMOR
Is a benign infiltrative odontogenic tumor It is most often
found in the mandibular molar / premolar region.
It is associated with an unerupted or impacted tooth.
CEOT is an infiltrative neoplasm and causes destruction with
local expansion. It is derived from the stratum intermedium and has a lower
growth potential. The mean age of occurrence is 40 year.
The histologically lesion appears as invasive infiltrative
islands in bone. These islands look like pure squamous cells with a high degree
of nuclear pleomorphism. The Liesegang rings (ovoid dystrophic calcifications),
a normal mature cytoplasm, and the lack of mitotic figures are the other
histological characteristic.
Radiographically, the Tumor appears as mixed radiolucent and
opaque masses, exhibiting a snow-driven appearance.
Treatment is surgical excision.
ODONTOGENIC MYXOMA
Is a benign odontogenic tumor of unknown origin. It generally
appears in the early third to fourth decades of life as a slow-growing
expansile lesion.
Tumor may produce jaw expansion.
Radiologically, it appears as well defined unilocular or
multilocular radiolucency.
A few stellate fibroblasts with copious amounts of hyaluronic
acid, scant collagen fibrils, and no capsule describe the histologic appearance
of this lesion.
Treatment is block excision.
ODONTOMA
Are hamartoma of odontogenic orgin. Odontoma are composed of
enamel, dentin, cementum and pulp tissue.
They are usually detected in adolescence and have a
predilection for the mandibular molar regions; however, they can be found in
other areas of the jaws.
Odontoma are of Two Types
Complex odontoma: An odontoma in which the various
odontogenic tissues appear in a haphazard arrangement that bears no resemblence
to teeth.
Compound odontoma : An odontoma in which the odontogenic
tissues are organized and bear a superficial resemblance to teeth.
This is the most common odontogenic tumor. It represents the
product of both histodifferentiation and morpho differentiation of odontogenic
tissues.
Treatment is the surgical removal.
PERIPHERAL ODONTOGENIC FIBROMA
Is benign proliferation of fibroblastic and odontogenic
epithelial component.
The tumor manifests as slow growing firm mass of attached
gingival.
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