Plasmacytoid myoepithelioma of a minor salivary gland.
Plasmacytoid myoepitheliomas are rare salivary gland neoplasms that probably represent a variant of the pleomorphic adenoma. They appear to occur more frequently in the minor salivary glands of the mouth. The mean average age at time of diagnosis of intraoral lesions is 18.8 years. Cytologic pleomorphism is a frequent histologic feature, which has led to a questionable diagnosis of malignancy in five out of ten cases. Caution is advocated in the evaluation of a salivary gland neoplasm with such features, and confusion with primary squamous cell or undifferentiated carcinoma of the salivary glands should be avoided. Patients who have cytologically pleomorphic lesions should be assessed for evidence of metastases. Rapid growth, neurologic evidence of sensory or motor dysfunction, and bone invasion should be regarded as ominous clinical parameters. Therapy should be directed toward complete surgical extirpation.