Spindle cell variant of ameloblastic carcinoma: a case report and review of literature

Ameloblastic carcinoma is a rare and malignant odontogenic tumor. Approximately, 100 cases of ameloblastic carcinomas have been reported in the literature, with fewer than 10 reported cases of an even more rare variant with spindle-cell differentiation. Although it is presumed that most ameloblastic carcinomas arise de novo, it also appears capable of proliferating as carcinoma ex ameloblastoma. Without a full past history, the exact origin of these tumors can be unclear. The exact classification becomes further questionable when both an intraosseous and peripheral tumor exists. This currently reported case has been present for at least 4 years before the patient presenting for care. However, without prior biopsy, the etiology and category of this ameloblastic carcinoma is speculative. Our case represents a histologically unequivocal case of ameloblastic carcinoma. Based on tumor morphology, questions still remain, as to whether it arose de novo, or as carcinoma ex ameloblastoma. The possibility of categorizing the current lesion as a spindle cell variant also exists because of the presence of a prominent population of malignant epithelial spindled cells arranged in fascicles. The authors believe that this ameloblastic carcinoma would best be subclassified as a rare spindle cell variant, based on the prominent spindle cell component.