Intraoral salivary duct carcinoma: A case report and a brief review.

Salivary duct carcinoma (SDC) is a rare, extremely aggressive malignancy arising in the ductal epithelium of the salivary glands. SDC occurs almost exclusively in the major salivary glands with parotid gland predominantly affected. Only isolated cases involving minor salivary glands have been reported in the literature. We report an unusual case of extensive SDC occupying the right cheek and the maxillary sinus, possibly arising from the minor glands of the buccal mucosa or from the mixed glands of the maxillary sinus in a 71-year-old man. The case was subjected to a panel of immunohistochemical markers like pan cytokeratin, low molecular weight cytokeratin (LMW CK), high molecular weight cytokeratin (HMW CK), CK 7, CK 20, CD 117, carcinoembryonic antigen (CEA), S-100, p63, Gross cystic disease fluid protein (GCDFP-15) and estrogen receptor (ER) to arrive at a definitive diagnosis.