Ameloblastoma

Findings:

Multiple axial and coronal CT images demonstrate an expansile lytic lesion involving the midline anterior mandible with a few internal calcifications. There is some bone remodeling, but the lesion is markedly expansile with several areas of bone interruption and other areas with imperceptibly thin cortex.

Discussion/Differential Diagnosis:

Expansile lytic lesion with cortical interruptions, unilocular or multilocular, with or without soft tissue mass

Slowly growing and painless, mandible>>maxilla, 30-50 yo most commonly.

Second most common odontogenic tumor behind odontoma but still rare.

Path- benign histology but locally invasive, histologically very similar to craniopharyngioma.

Imaging-CT expansile lytic multisepatated, MR nodular peripheral enhancing to dist from other lesions.

En-bloc resection due to local curettage having high recurrence rate (45-90%).

Malignant, more aggressive variants: ameloblastifc carcinoma, malignant ameloblastoma (mets)

Ddx of mandibular cystic lesions:

Dentigerous cyst- crown of unerupted tooth (some amelo may arise from preeexisting dentigerous cyst)

Radicular cyst- roots- most common- caries

Odontogenic keratocyst- more aggressive, multilocular, impacted tooth, thin poorly enhancing walls

Odontogenic myxoma- may be indistinguishable

Others: ABC, giant cell granuloma, fibrous dysplasia

Additional cases:                -ameloblastoma
                                       -ameloblastoma2

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