PRIMARY SQUAMOUS-CELL CARCINOMA OF ACCESSORY PAROTID-GLAND DUCT EPITHELIUM - REPORT OF A CASE

A rare case of primary squamous cell carcinoma surrounding Stensen's d uct in a 75-year-old man is presented. The tumor was a relatively well -defined, hard, subcutaneous mass, measuring 18 x 14 x 9 mm and situat ed in the right cheek. Microscopic examination of an excisional biopsy specimen revealed tumor cells showing squamous differentiation, a pap illary growth pattern, and ductal structures with comedo necrosis. Imm unohistochemical studies showed positive reactivity for KL-1 (cytokera tin, monoclonal), epithelial membrane antigen, and carcinoembryonic an tigen in some tumor cells. The origin of the tumor was thought to be t he accessory parotid gland duct epithelium.