Metastatic renal cell carcinoma presenting as a parotid tumor: a case report with immunohistochemical findings and a review of the literature.

Renal cell carcinoma presenting as an asymptomatic parotid mass is rare. Only 15 cases have been reported. We describe a 72-year-old man with widespread metastatic renal cell carcinoma presenting with a 2-year history of a slowly enlarging left parotid mass. Needle biopsy revealed a clear cell neoplasm. Immunoperoxidase studies for carcinoembryonic antigen were negative while those for vimentin and keratin were positive, consistent with a renal cell carcinoma. This is the first case reported in which the immunohistochemical findings of positive staining for vimentin and keratin have confirmed the presence of metastatic renal cell carcinoma. The histochemical features of various parotid clear cell tumors, as well as a review of renal cell tumors presenting as a parotid mass, will be discussed.