Odontogenic Tumors Quiz

Odontogenic Tumors

• Odontogenic tumors are tumors arising from tissues associated with teeth.

Odontogenic Epithelium and Ectomesenchyme

• Outer enamel epithelium, stellate reticulum, stratum intermedium, inner enamel epithelium, dental papilla, and dental follicle are crucial components involved in tooth development.
• These structures are crucial for understanding odontogenic tumors' origins.

Tissue of Origin

• Epithelial only: Ameloblastoma, CEOT (Calcifying epithelial odontogenic tumor), AOT (Adenomatoid odontogenic tumor).
• Ectomesenchymal only: Cementoblastoma, Odontogenic myxoma.
• Epithelial and ectomesenchymal: Ameloblastic fibroma, Odontoma.
• Primary intraosseous carcinoma of the jaws are also included in the classifications of odontogenic tumors.

Ameloblastoma

• Benign tumor with persistent and aggressive growth.
• Originates from the enamel organ.
• 2022 WHO Classification: Conventional ameloblastoma, Unicystic ameloblastoma, Extraosseous/peripheral ameloblastoma.

Conventional Ameloblastoma: Clinical Features

• Accounts for about 80% of ameloblastomas.
• Most commonly present in the 4th and 5th decades.
• Found mostly in the mandible's posterior body and ramus, affecting 85% of cases.
• Characterized by slow, painless expansion in the buccal/lingual dimension.

Ameloblastoma: Radiographic Features

• Solitary lesion, usually arising in the alveolar process, but sometimes pericoronal.
• Radiographic appearance: well-defined, corticated, and irregular radiolucency, ranging from 1 to 10 cm or larger.
• Often unilocular, especially in smaller lesions, or multilocular with coarse trabeculae.
• Irregular outline expanding and eventually resorbing the cortex.
• Tooth displacement and root resorption are common.

Unicystic Ameloblastoma

• Accounts for approximately 15% of ameloblastomas.
• Develops from odontogenic cyst epithelium, or de novo as a neoplasm.
• Usually a cystic lesion appearing in the second or third decade (younger than conventional ameloblastoma).
• Occurs predominantly in the mandible, usually posterior.
• Typically asymptomatic, but large lesions can cause jaw expansion.
• Often pericoronal, well-defined, corticated, round or oval radiolucency, typically unilocular.
• May cause tooth displacement, root resorption, and cortical resorption.

Extraosseous/Peripheral Ameloblastoma

• Accounts for about 1% of all ameloblastomas.
• Originates from odontogenic epithelial rests in the gingiva, or occasionally from basal cells of surface epithelium.
• Mostly found in middle-aged adults (average age 52).
• Characterized by a painless, sessile, or pedunculated mass on the gingiva, most commonly found in the posterior mandible.

Calcifying Epithelial Odontogenic Tumor (CEOT)

• Benign odontogenic tumor that resembles ameloblastoma clinically and radiographically.
• Originates from the enamel organ.
• Commonly found in adults during the 4th and 5th decades, with the majority (75%) in the mandible, specifically the molar-ramus area.
• Characterized by slow, painless enlargement of the jaw, often evident as a prominent buccal-lingual expansion.
• Radiographic appearance: solitary lesion in the alveolar process (50% pericoronal), well-defined, unilocular or multilocular lesion, frequently corticated.
• May exhibit radiolucent areas alone, or radiolucent areas with radiopaque foci that may cluster near the crown of a pericoronal lesion.
• Common general effects include cortical expansion and resorption, with root resorption and displacement.
• Exhibit "Driven snow" pattern in radiographic imaging.
• Histological features include sheets of large, polygonal eosinophilic cells; pleomorphic cells with large nuclei (but benign); and concentric calcifications (Liesegang rings).
• Amyloid-like material is often present, staining with Congo red and thioflavin T.
• Treatment involves conservative excision, which is often effective. Has better prognosis than ameloblastoma.

Adenomatoid Odontogenic Tumor (AOT)

• Benign odontogenic tumor of epithelial origin, arising from the enamel organ.
• Epithelial cells form patterns resembling glandular tumors.uu
• Primarily in the first and second decades, exceedingly rare after 30.
• Predominantly found in females (2:1 ratio). Usually in the anterior maxilla.
• Generally small (less than 3 cm). Larger lesions can cause buccal-lingual expansion and are often asymptomatic.
• Radiographic appearance: solitary, well-defined, often corticated unilocular or multilocular lesion (75% pericoronal). Pericoronal lesions typically extend apically beyond the cementoenamel junction, differentiating it from dentigerous cysts.
• Treatment typically involves sufficient enucleation due to the tumor's thick capsule.
• Prognosis is excellent with a rare recurrence rate.

Primary Intraosseous Carcinoma of the Jaws

• Carcinoma in the jaw with no connection to oral or skin epithelium.
• Often termed odontogenic carcinoma.
• May arise de novo, or in a pre-existing cyst, tumor.
• Residual radicular cysts and dentigerous cysts are potential sources.
• Mucoepidermoid carcinomas may originate from mucus cells in dentigerous cysts.
• Mostly affecting older adults in their 60s. Predominantly found in males.
• Common symptoms include pain and swelling.
• Radiographically: Radiolucency with irregular, ragged periphery.
• Histologically: Squamous cell carcinoma originating from the bone's epithelial lining, and mucoepidermoid carcinomas can be seen, originating from dentigerous cysts.
• Treatment involves resection, with or without chemotherapy and/or radiation.

Cementoblastoma

• Benign odontogenic tumor arising from cementoblasts.
• Commonly detected in late teens to early 20s.
• Most prevalent in the mandible, specifically the area of the first molar, with 75% occurring in the mandible, and 90% associated with the molar/premolar region.
• Typically painless but may exhibit symptoms of pain and swelling.
• Radiographically: Solitary lesion attached to tooth root. Commonly the first molar. Calcified mass attached to the tooth root, obscuring the root's outline. Radiopacity is often lobulated or radiating. Peripheral radiolucency is frequently present.
• Treatment involves removal of both the tooth and the attached tumor.
• Has excellent prognosis if completely removed.
• Histological features show sheets and trabeculae of cementum fused to the root with irregular lacunae. Multinucleated cells/blast cells line the trabeculae. Cellular fibrovascular connective tissue typically exists in-between the trabeculae.

Odontogenic Myxoma

• Benign ectomesenchymal odontogenic tumor.
• Resembles developing tooth microscopically.
• Most common in young adults (mean age 25-30), with a wide age range.
• Found slightly more often in mandible.
• Equally common in anterior and posterior locations.
• Generally asymptomatic, though larger lesions can cause slow, painless expansion, with potential for quick growth due to accumulated ground substance.
• Can cause pain, tooth and root resorption.
• Radiographically: Solitary lesion in the alveolar process, typically unilocular or multilocular, with an often irregular radiolucency. May exhibit delicate trabeculae, a "honeycomb" pattern. Can be large.
• Histologically: Characterized by delicate myxomatous connective tissue containing a ground substance matrix, mainly hyaluronic acid and chondroitin sulfate. Also has a few spindle shaped fibroblasts without a capsule. Resembles a dental papilla.
• Treatment involves curettage for small lesions or excision for larger ones.

Ameloblastic Fibroma

• Benign tumor of epithelial and ectomesenchymal odontogenic tissue.
• Most prevalent in the first and second decades of life.
• Equal frequency in males and females.
• Predominantly found in the posterior mandible (molar-ramus region) or maxilla.
• Asymptomatic. However, larger lesions can result in jaw expansion
• Radiographically: Solitary pericoronal (75%) lesion. Often well-defined, corticated radiolucency of variable size. Unilocular or multilocular.
• Potential for extending lesions into the jaw's ramus and body. Displacement of teeth and root resorption may occur in lesions.
• Histologically: Cords and islands of cuboidal odontogenic epithelium resembling ameloblastoma. Fibrous stroma with delicate tissue and mesenchymal cells similar to dental papilla.
• Treatment can be conservative excision, which is usually sufficient, with wider excision in recurrence cases.
• Rare transformation to ameloblastic fibrosarcoma.

Odontoma

• Benign odontogenic lesion of ectodermal and ectomesenchymal origin.
• Often considered a hamartoma rather than a neoplasm.
• Characterized by producing dental tissues (enamel, dentin, pulp) - commonly referred to as a "tooth tumor".
• Most common odontogenic lesion. Two types: compound and complex.
• Compound Odontomas are usually found in the anterior maxilla. These produce little teeth arranged in a well-organized manner, containing enamel, dentin, and pulp.
• Complex Odontomas typically occur in the posterior mandible or maxilla. They form an amorphous, jumbled mass of dental hard and soft tissues without distinct tooth forms.
• Radiographically: Compound Odontomas show multiple small tooth-forms, and complex Odontomas show an amorphous, radiopaque mass of dental tissues.
• Treatment involves excision; peripheral fibrous connective tissue capsule usually allows for complete removal.
• Recurrence rate is very rare.