Myoepithelial Carcinoma arising from a Parotid Pleomorphic Adenoma A Case Report

Abstract

Myoepithelial carcinoma is a rare neoplasm, accounting for less than 2% of all salivary gland carcinomas and can arise de novo or secondary to a previous pleomorphic adenoma, as in the case presented here. The presence of mitoses, foci of necrosis, characteristic histomorphology, and exclusive proliferation of myoepithelial cells identified by immunohistochemistry confirm the diagnosis. The gold standard of therapy is surgical resection with clear margins; however, the risks of local recurrence and distant metastasis are 35% and 22%, respectively. Our case corresponds to a 65-year-old patient who underwent surgery for a pleomorphic adenoma, which recurred after 5 years. She presented to our clinic with a myoepithelial tumor of 2 months’ evolution with involvement of the facial nerve and soft tissues. Due to its rapid growth, this is an unusual presentation.