Ameloblastoma — Overview
Ameloblastoma is the most common clinically significant odontogenic tumour. It is benign but locally aggressive, arises from odontogenic epithelium, and shows a strong predilection for the posterior mandible (molar–ramus region).
Classification
- Conventional (solid/multicystic) — most common, locally aggressive, high recurrence.
- Unicystic — younger patients, better prognosis, often associated with an impacted tooth.
- Peripheral (extraosseous) — soft tissue, least aggressive.
- Malignant / metastasizing — rare.
Histologic patterns (mnemonic FUPA-D): Follicular, Unicystic, Plexiform, Acanthomatous, Desmoplastic. The follicular pattern is most common.
Clinical & Radiographic Features
Slow-growing, painless swelling causing bony expansion. Classic radiograph: multilocular "soap-bubble" or "honeycomb" radiolucency with possible root resorption and tooth displacement.
Histopathology
Peripheral tall columnar ameloblast-like cells with reverse polarity (nuclei away from basement membrane) and subnuclear vacuolation, surrounding a loose stellate-reticulum-like centre.
Treatment
Solid/multicystic types require resection with a margin (recurrence is high with curettage). Unicystic and peripheral types are managed more conservatively.
Exam Tips ⭐
Soap-bubble + posterior mandible + reverse polarity = ameloblastoma. Differentiate from OKC (which grows antero-posteriorly without much expansion).