Pleural fluid metastases of myoepithelial carcinoma: A case report and review of the literature.

Myoepithelial carcinoma (MECA) is one of the rarest salivary gland neoplasms, which may either arise de novo or develop within a preexisting pleomorphic adenoma or benign myoepithelioma. The tumor occurs mainly in the parotid gland followed by minor salivary glands and other body sites. As a result of their morphologic heterogeneity, they can be confused easily with many tumors. Awareness of their unique cytoarchitectural patterns and immunohistochemical profile is crucial for accurate identification. Herein, we report a rare case of a 51-year-old female patient with MECA of the maxillary sinus that metastasized to the pleural fluid. To the best of our knowledge, this is the first case of pleural fluid involvement by MECA reported in the literature.