Intraoral salivary duct carcinoma: case report with immunohistochemical observations.

Salivary duct carcinoma is an uncommon malignant salivary gland tumor that occurs predominantly in the parotid gland. Oral involvement is extremely rare, with few cases having been reported in the literature. The tumor is characterized by an aggressive behavior and has a poor prognosis. We describe a case of salivary duct carcinoma arising in the hard palate of a 63-year-old man. Immunohistochemical analysis revealed that tumor cells tested positive for cytokeratin, epithelial membrane antigen, proliferating cell nuclear antigen, Ki67, p53, laminin, and collagen IV. Despite radical surgical resection, bilateral neck dissection, and postoperative radiotherapy, liver metastases developed, and the patient subsequently died of his disease.