Pleomorphic adenoma with predominant plasmocytoid myoepithelial cells: a diagnostic pitfall in aspiration cytology. Case report and review of the literature.

Fine-needle aspiration (FNA) biopsy of the salivary gland is a sensitive and specific diagnostic tool. However, diagnostic problems are sometimes encountered in interpreting some cases, not only in differentiating benign from malignant cases but also in the specific classification of these neoplasms. We report a case of a pleomorphic adenoma with predominant plasmocytoid myoepithelial cells arising in minor salivary glands from the hard palate in a 78-year-old patient, which was falsely diagnosed as a carcinoma on liquid-based cytology (ThinPrep (TP)). The differential diagnosis of salivary gland tumors with predominant myoepithelial cells on FNA biopsy is discussed.