Undifferentiated carcinoma arising from the Stensen's duct: a case report and review of the literature.

Primary carcinoma arising in Stensen's duct is an extremely rare and poorly understood tumor. A 38-year-old man was referred with a malignant lesion situated in the right cheek. The patient was treated by local resection, total parotidectomy, and modified radical neck dissection. Microscopic examination revealed tumor cells of basaloid pattern with squamous differentiation in some areas. The tumor showed a very aggressive behaviour with early local recurrence and metastatic disease. The histological and radiological findings suggest the origin from the Stensen's duct. Primary carcinoma of Stensen's duct should be histologically consistent with epidermoid, mucoepidermoid, or undifferentiated carcinoma. The diagnosis of true Stensen's duct carcinoma can be performed on the basis of clinical presentation, radiological findings, and tumor histology. Criteria for determination of origin in the duct are revised and compared with this case.