Multicystic (solid conventional) – 86% Unicystic – 13% Peripheral – 1%

Odontogenic Tumors Flashcards by Kevin Kemarly

Odontogenic Tumors: 3 Tissue categories of origin

Odontogenic Epithelium
Mesenchymal
Mixed

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Tumors of Odontogenic Epithelium

Ameloblastoma
Adenomatoid odontogenic tumor
Calcifying epithelial odontogenic tumor
Squamous odontogenic tumor

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Ameloblastoma types

Multicystic (solid conventional) – 86%
Unicystic – 13%
Peripheral – 1%

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Ameloblastoma stats

• Usually 3rd to 7th decades, no gender predilection
• 85% mandible (molar/ramus most common), 15% maxilla
(usually posterior)

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Ameloblastoma - Radiographic

• Multilocular radiolucency usually; soap bubble (large loculations),
honeycomb (small loculations)
• Buccal and lingual cortical expansion
• Often associated with an unerupted tooth (3rd molar)
• Margins may show irregular scalloping

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Ameloblastoma and roots

Resorption of
adjacent tooth
roots is
common

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Ameloblastoma – Treatment and Prognosis

• Enucleation and curettage (recurrence 50% to 90%)
• Marginal resection (recurrence up to 15%)
• En bloc resection, with at least 1 cm clear margins (highest cure rate)
• Radiation therapy not recommended, except to control nonresectable
tumors.

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Desmoplastic Ameloblastoma

• The exception to the rules for conventional
ameloblastoma
– One of several histologic subtypes of ameloblastoma
– Preference for anterior jaws, most often maxilla
– Radiographically resembles a fibro-osseous lesion
– Mixed radiolucent/radiopaque appearance due to osseous
metaplasia within dense fibrous septa
– Varying opinions regarding aggressiveness of tumor and
recommended treatment

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Unicystic Ameloblastoma

• 50% diagnosed during the second decade of life
• Over 90% are found in the mandible, usually posterior
• Circumscribed radiolucency, often surrounding the crown of an
unerupted third molar, similar to dentigerous cyst

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Unicystic Ameloblastoma Dx guidlines

To be diagnosed as unicystic, the
ameloblastoma must be unicystic grossly,
radiographically, and histologically

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Unicystic Ameloblastoma – Treatment and

Prognosis

• Enucleation is most common, although if the tumor is found to be
mural (satellites of ameloblastic epithelium within wall of cyst),
further treatment is indicated
• 10% to 20% recurrence after enucleation

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Peripheral Ameloblastoma

• 1% of ameloblastomas
• GUM BUMP - Painless, non-ulcerated, sessile or pedunculated lesion
on gingiva or alveolar mucosa; usually posterior, more common in
mandible
• Average age 52
• Innocuous behavior. Local surgical excision recommended, with 15%
to 20% recurrence initially; second recurrence is rare.
• Rule out central ameloblastoma

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Gum Bump Differential

Pyogenic granuloma
Fibroma
Ossifying fibroma
Peripheral giant cell
granuloma
Parulis
Others: Peripheral
odontogenic fibroma,
peripheral ameloblastoma

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Malignant Ameloblastoma

• Less than 1% of all ameloblastomas
• Metastasis, with secondary tumors exhibiting histology similar to
primary tumor (benign cytology under the microscope)
• Mets to lungs most common… aspiration or implant mets. Metastasis
may also occur via blood or lymphatic channels
• Poor prognosis

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Ameloblastic Carcinoma

• Cytologic features of malignancy either in primary or secondary
tumors (microscopically ugly)
• More aggressive, with ill-defined margins, destruction of cortex, and
extension into soft tissue
• Poor prognosis

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Adenomatoid Odontogenic Tumor (AOT)

• 3%-7% of odontogenic tumors
• “Two thirds tumor”: Female, young (ages 10 to 19), anterior jaws,
maxillary, associated with impacted tooth, radiopacities
• Most often asymptomatic, less than 3 cm. May cause painless bony
expansion if large

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Adenomatoid

Odontogenic Tumor

2/3’s tumor:
Female
Anterior
Maxillary
Young
Canine tooth

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Adenomatoid Odontogenic Tumor – Radiographic

Features

• Unilocular radiolucency
• May contain fine calcifications – snowflake calcifications (mixed
RL/RO DDX)
• “Follicular” - associated with crown of unerupted tooth
• “Extrafollicular” – associated with or between tooth roots

Adenomatoid Odontogenic Tumor – Treatment

and Prognosis

Enucleates very easily due to thick capsule
Recurrence after enucleation is rare
No reports of aggressiveness

Calcifying Epithelial Odontogenic Tumor

CEOT, aka Pindborg Tumor

Less than 1% of odontogenic tumors, less than 200 reported cases
Wide age range, most common between 30 and 50 years
No gender predilection
Two thirds of cases reported in the mandible, usually posterior
Painless, slow growth

Calcifying Epithelial Odontogenic Tumor

(CEOT) - Radiographic

• Radiolucent defect, most often multilocular
• Margins may be scalloped
• Frequent association with an impacted tooth, usually a mandibular
third molar
• Often contains calcifications that vary in density and size,
concentrated around crown of impacted tooth – amyloid material and
Leisegang calcifications

Calcifying Epithelial Odontogenic Tumor –

Treatment and Prognosis

Conservative resection, including a narrow rim of surrounding bone
Posterior maxillary lesions may require more aggressive treatment
Recurrence rate 15%
Good prognosis

Tumors of Odontogenic

Ectomesenchyme

Odontogenic Fibroma (central)
Granular Cell Odontogenic Tumor
Odontogenic Myxoma
Cementoblastoma

Odontogenic Fibroma

• Histology may look the same as a hyperplastic dental
follicle – correlation with clinical and radiographic
presentations necessary

Odontogenic fibroma locations

• 45% maxillary, mostly anterior to the first premolar • 55% mandible, half of which are posterior to the first molar

Odontogenic fibroma gender predilection and avg age

* Wide age range, mean age 40 years | * F>M, app 2:1

Clinical and radiographic presentation of Odontogenic Fibroma

• Clinical notch or depression in the palate is characteristic of maxillary OF’s • Small lesions appear unilocular; large lesions can appear multilocular • 12% exhibit radiopaque flecks • Root resorption is common; also root divergence • Two accepted histologic presentations: simple type and WHO type

Odontogenic fibroma tx and prognosis

* Enucleation and vigorous curettage | * Recurrences uncommon, prognosis good

Odontogenic Myxoma age, location and gender facts

• Commonly young adults, average age 25-30 years, no gender predilection • Any location within jaws, mandible more common

Odontogenic Myxoma Radiographic appearance

• Radiographic: Uni- or multilocular radiolucency, irregular or scalloped margins • Thin trabeculae of bone arranged at right angles • May exhibit a soap bubble pattern

Odontogenic Myxoma – Treatment and Prognosis

• Small lesions may be treated with curettage, but follow-up is necessary • Larger lesions may need resection due to infiltration of surrounding bone • Recurrence near 25% • Overall good prognosis, no reported metastases • Rare myxosarcoma: cellular atypia and more aggressive; No metastasis

Cementoblastoma

``` • Age: Young adults; <25 yrs • Sex: No predilection (M?) • Site: 75% in mandible, 1st molar • Radiographic: Pathognomonic – attached to a tooth root • Clinical: May be painful and expansile • Completely excise ```

Mixed Odontogenic Tumors

* Composed of ectomesenchymal and odontogenic epithelial elements * Compound and complex odontomas * Ameloblastic fibroma * Ameloblastic fibro-odontoma * Ameloblastic fibrosarcoma

Odontoma

Hamartoma (developmental anomaly) • Compound – multiple small structures resembling teeth; most common • Complex – conglomeration of enamel and dentin • Mean age is 14 years • More common in the maxilla • Usually asymptomatic, associated with failure of tooth eruption

Odontoma Radiographic presentation

Radiographically exhibits radiodensity similar to teeth, | surrounded by a narrow radiolucent rim

Odontoma Tx

Local excision, excellent prognosis

Ameloblastic Fibroma

• Both the epithelial and mesenchymal tissues are neoplastic • Most often diagnosed within first two decades of life; males slightly outnumber females • 70% posterior mandible; may grow large • Radiographically, unilocular or multilocular radiolucency, welldefined, possibly sclerotic border • 75% associated with unerupted tooth

Ameloblastic Fibroma – Treatment and Prognosis

• Initial lesions are treated conservatively, with local excision or curettage • Recurrent lesions are treated with more aggressive surgical resection • Recurrence rates reported from 0 to 45% after conservative removal

Ameloblastic Fibro-Odontoma

• Similar to ameloblastic fibroma, but contains enamel and dentin • Average age of diagnosis is 10 years (younger than ameloblastic fibroma)

Ameloblastic Fibro-Odontoma Radiographically

Radiographically contains variable amounts of calcified material as small radiopacities or large comglomerations; often associated with an unerupted tooth

Ameloblastic fibro odontoma

Treatment consists of conservative curettage, shells out easily; recurrence is rare, prognosis is excellent

Ameloblastic Fibrosarcoma

• Malignant counterpart of ameloblastic fibroma • Mesenchymal tissue is malignant • 45% of cases arise from a recurrence of ameloblastic fibroma or ameloblastic fibro-odontoma • 1.5 times as common in males, average age 27 years • 80% occur in the mandible, exhibiting pain, swelling, and rapid growth

Ameloblastic Fibrosarcoma | Radiographically

ill-defined radiolucency, destructive

Ameloblastic Fibrosarcoma | Treatment

``` Radical surgery is recommended • Death usually occurs due to uncontrolled, aggressive local disease ```