a benign epithelial odontogenic tumor appearing radiographically as a well-circumscribed radiolucent-radiopaque lesion usually surrounding the crown of an impacted tooth in an adolescent or young adult; characterized histologically by columnar cells organized in a duct-like configuration interspersed with spindle-shaped cells and amyloid-lie deposition that gradually undergoes dystrophic calcification. Syn: adenoameloblastoma, ameloblastic adenomatoid tumor.