Carcinoma of the parotid gland duct. Rare differential diagnosis of a tumor in the cheek.

Background: Carcinomas arising in the parotid duct (Stensen's duct) are ext remely rare, and only a few cases have been reported. Patients: We present another case of a squamous cell carcinoma of Stensen's duct. Clinical aspec ts, diagnosis, and therapy are discussed, as is the differential diagnosis of tumors in the cheek region. Results: Results of clinical and imaging inv estigations are typical of a malignant tumor. Differential diagnosis of a n odule in the region of the Stensen's duct includes salivary and metastatic tumors of the parotid gland and the accessory parotid gland tissue as well as carcinomas of the oral mucosa and the skin that invade the duct. Nonneop lastic conditions may cause swelling in the cheek region that simulates a t umor. Such conditions inculde salivary calculi, tumor-like inflammatory nod ules, strictures of the duct, congenital stenosis, and diverticulum. Conclu sions: The preoperative diagnosis of a primary Stensen's duct carcinoma rem ains difficult. Diagnosis requires clinical, histological, and intraoperati ve exclusion of a primary tumor originating elsewhere in the cheek region a s well as metastatic disease and nonneoplastic lesions.