Pleural fluid metastases of salivary duct carcinoma: A case report and review of the literature

Salivary duct carcinoma (SDC) comprises a small proportion of salivary gland tumors; however, it is known to be aggressive with a high rate of metastasis. Although frequent references are made to pulmonary dissemination, metastases in the pleural fluid have not been described. In this article, we report the cytologic features of metastatic SDC in the pleural fluid. The clinical history, cytomorphology and immunohistochemical features used for diagnosis are described. To the best of our knowledge, this is the first case of pleural fluid involvement by salivary duct carcinoma reported in the literature.