Myoepithelioma of the head and neck: case report and review.

The clinical, light, and ultrastructure features of a myoepithelioma occurring on the hard palate of a 24-year-old woman are presented and compared with 41 myoepithelioma of the head and neck described in the English literature. These 42 tumors (39 benign and 3 malignant) occurred in individuals from 14 to 81 years of age, affected both sexes about equally, and most often presented as a slowly enlarging, asymptomatic mass. The parotid gland and palate were the most common sites of occurrence. The tumors are typically circumscribed and encapsulated, vary from 1 to 5 cm in the greatest dimension, and are composed of spindled and/or plasmacytoid myoepithelial cells. Prognosis correlates with histologic appearance and parallels that of the pleomorphic adenoma. Conservative excision with a margin of uninvolved tissue is curative. The differential diagnosis and histogenic relationship with other closely related neoplasms are discussed.