Dedifferentiated Epithelial-Myoepithelial Carcinoma: Analysis of a Rare Entity Based on a Case Report and Literature Review
International Journal of Surgical Pathology
Published online on December 05, 2012
Abstract
Dedifferentiated epithelial–myoepithelial carcinoma (DEMC) is very rare salivary gland neoplasm with only anecdotal reports. We present an analysis of DEMC, based on a case and review of literature. Our patient, an 85-year-old woman, presented with a submandibular mass of 5 years duration that was increasing in size over a 5-week period. Histologically, there were areas of typical epithelial–myoepithelial carcinoma, with dedifferentiation of both components, manifesting morphologically as salivary duct carcinoma and areas of myoepithelial carcinoma. A review of literature revealed 21 previously reported cases of DEMC. DEMC occurs at an average age of 72 years, most often in the parotid gland (72%) followed by submandibular gland (17%). Dedifferentiation more often involves the epithelial component (13/15 cases) than the myoepithelial component (5/15 cases). Although typical epithelial–myoepithelial carcinomas are fairly indolent (average disease-free survival of 11.34 years), dedifferentiation confers a poor prognosis (survival reported from 1 to 72 months).