title: [Secondary high-malignant transformation of a low-malignant epithelial-myoepithelial carcinoma].
abstract: The rare entity of epithelial-myoepithelial carcinoma (EMC) belongs to a group of tumors with a biphasic ductular growth pattern, mostly with a dominating myoepithelial component and low-grade malignancy. We report on the rare constellation of a primary low-malignant EMC with high malignant transformation (so-called dedifferentiation) into a highly malignant myoepithelial carcinoma. In the eight published cases so far, the high-malignant component was reported to be either adenocarcinoma or undifferentiated carcinoma or was otherwise not specified. To the best of our knowledge, this is the first case report of a high-grade myoepithelial carcinoma transforming from a low-grade EMC. We discuss interesting parallels to the pathogenesis of secondary transformation of carcinoma ex pleomorphic adenoma.
authors.affiliation: Pathologisches Institut, Ludwig-Maximilians-Universität München, Thalkirchner Strasse 36, 80337 München. Manuel.Niederhagen@med.uni-muenchen.de
authors.forename: M
authors.initials: M
authors.lastname: Niederhagen
authors.forename: P
authors.initials: P
authors.lastname: Zengel
authors.forename: S
authors.initials: S
authors.lastname: Ihrler
mesh_terms: D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis; D054337:Cell Dedifferentiation; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D009208:Myoepithelioma / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D009361:Neoplasm Invasiveness; D010306:Parotid Gland / Q000473:pathology / Q000601:surgery; D010307:Parotid Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery
chemical_list: D014408:Biomarkers, Tumor