Ameloblastic carcinoma ex ameloblastoma of the mandible with malignancy-associated hypercalcemia.

Ameloblastoma is a rare, locally destructive, benign neoplasm of the jawbones, which arises from epithelium derived from the epithelial components of the developing tooth. Ameloblastic carcinoma is the term used to designate any ameloblastoma in which there is histologic evidence of malignancy in the primary tumor, regardless of whether it has metastasized. Most ameloblastic carcinomas are presumed to have arisen de novo, with few cases of malignant transformation of ameloblastoma being apparent. Hypercalcemia is the most common metabolic complication of malignancy. Although malignancy-associated hypercalcemia is often reported in association with other malignancies, it is exceedingly unusual in association with ameloblastoma, malignant ameloblastoma, or ameloblastic carcinoma. We describe a patient with multiple recurrences of ameloblastoma, with subsequent malignant transformation presenting with malignancy-associated hypercalcemia.