title: Dedifferentiated epithelial-myoepithelial carcinoma: analysis of a rare entity based on a case report and literature review.
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).
authors.affiliation: 1Penn State College of Medicine & Penn State Milton S. Hershey Medical Center, Hershey, PA, USA.
authors.forename: Aaron R
authors.initials: AR
authors.lastname: Baker
authors.forename: Sara E
authors.initials: SE
authors.lastname: Ohanessian
authors.forename: Eelam
authors.initials: E
authors.lastname: Adil
authors.forename: Henry S
authors.initials: HS
authors.lastname: Crist
authors.forename: David
authors.initials: D
authors.lastname: Goldenberg
authors.forename: Haresh
authors.initials: H
authors.lastname: Mani
mesh_terms: D000369:Aged, 80 and over; D002277:Carcinoma / Q000473:pathology*; D054337:Cell Dedifferentiation; D005260:Female; D006801:Humans; D009208:Myoepithelioma / Q000473:pathology*; D013365:Submandibular Gland Neoplasms / Q000473:pathology*; D013997:Time Factors