Ameloblastic Carcinoma of the Maxilla: Report of a Case

Ameloblastic carcinoma was first described by Robinson.1 It is a rare malignant odontogenic tumor that has microscopic features of ameloblastoma intermingled with those of carcinoma. Various classifications have been developed to categorize odontogenic carcinomas. Since the initial World Health Organization classification system for odontogenic tumors, various revisions of this classification have been published.2,3 Kramer et al4 in 1992 proposed the following 4 categories: 1) malignant ameloblastoma, 2) primary intraosseous carcinoma, 3) malignant variant of other odontogenic epithelial tumors, and 4) malignant changes in odontogenic cyst. However, at this time Slootweg and Muller’s5 classification is the most broadly accepted. It divides odontogenic carcinomas into: type 1: primary intraosseous carcinoma ex-odontogenic cyst; type 2: malignant ameloblastoma and ameloblastic carcinoma, arising de novo, ex-ameloblastoma or ex-odontogenic cyst; and type 3: primary intraosseous carcinoma arising de novo, which is subdivided into nonkeratinizing and keratinizing types. This classification considers the ameloblastic carcinoma to be different from other odontogenic tumors. The term “ameloblastic carcinoma” tends to describe ameloblastomas that exhibit microscopic features of malignancy without metastatic growth, whereas the “malignant ameloblastomas” are cytologically benign tumors that unexpectedly metastatize.6 Lolachi et al7 reported that there was a total of 34 cases of ameloblastic carcinoma in the English literature. Nagai et al8 collected 46 ameloblastic carcinomas from the English and Japanese literature. Only 14 cases have occurred in the maxilla. This is the fifteenth case in this rare location. Report of Case