Intraoral salivary duct carcinoma: a clinicopathological study of four cases and review of the literature.

Salivary duct carcinoma (SDC) is a distinctive entity of highly malignant salivary gland tumors. We present the clinical features and outcomes of four cases in minor salivary glands and of 69 additional cases previously reported in the literature. The tumor occurs most frequently in the sixth and seventh decades of life with a 3.8:1 male preponderance. The prognosis is dismal. Sixty-one percent of patients were dead within 5 months to 10 years (mean 25 months) and the rate of lymph node metastasis was 60%. Twenty-eight percent of patients were without evidence of the disease for 13 months to 9 years (mean 33 months). The histologic features, differential diagnosis, and origin of SDC are discussed.