Ameloblastic carcinoma: a clinicopathologic study and assessment of eight cases.

The term ameloblastic carcinoma is differentiated from the term malignant ameloblastoma and is defined as an ameloblastoma in which there is histologic evidence of malignancy in the primary tumor or the recurrent tumor (or metastasis), regardless of whether it has metastasized. Eight cases of ameloblastic carcinoma from the Armed Forces Institute of Pathology (AFIP) are reported. The mean age of patients was 30.1 years, with no sex predilection noted. Seven cases involved the mandible and one involved the maxilla, with the posterior regions favored. The most common sign was swelling, although pain, rapid growth, trismus, and dysphonia also occurred. Lesions characteristically were evident as ill-defined destructive radiolucencies, with occasional radiopacities noted. Histologic features generally resembled those of conventional ameloblastoma but with cytologic features of epithelial malignant disease. The clinical course was uniformly aggressive with extensive local destruction and spread, frequent recurrences, and one case of neck node metastasis. The nomenclature and classification of odontogenic carcinomas are discussed, as well as entities that should be included in the differential diagnosis. Further reporting of ameloblastic carcinoma is encouraged.