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

Spindle cell variant of ameloblastic carcinoma is an extremely rare tumor. Severe dedifferentiated spindle cell variants are diagnostically challenging, particularly in small biopsy specimens. Here, we report a case of spindle cell variant of ameloblastic carcinoma in the mandible of a 69-year-old male patient and review the available literature. The tumor was surgically resected under general anesthesia. Histopathologic diagnosis of spindle cell carcinoma was made on incisional biopsy, and the final diagnosis was confirmed as spindle cell variant of ameloblastic carcinoma. Immunohistochemistry using cytokeratin and CK19 is helpful in determining the origin of spindle cell variant of ameloblastic carcinoma, particularly CK19 indicated that sarcomatoid spindle cells are derived from odontogenic epithelium. A review demonstrated higher mean age of patients compared with that of other types of ameloblastic carcinoma. The rates of mortality and local recurrence were concurrently 30%. No recurrence or metastasis was seen in the 23-month follow-up period in the present case.