title: Mixed epithelial and stromal tumor of the middle ear: The first case report.
abstract: We report a tumor arising in the middle ear of a 65-year-old female patient that was composed of an ovarian-type stroma (OS) and an epithelial component. The tumor consisted of irregular, polypoid masses containing multiple variably sized cystic spaces, which were invariably surrounded by the OS. The cystic spaces were lined by flat, cuboidal, or columnar epithelial cells, in most parts showing mucinous differentiation. The epithelial lining of the cysts strongly expressed cytokeratins AE1-3, CK7, CK8, CK18, CK19, EMA, and S100 protein. The stroma expressed CD34 and smooth muscle actin. No cytological atypia or mitoses were present, and the proliferative activity was less than 1% in both components. The clonality analysis proved the clonal nature of the neoplasm. We believe that this tumor is a new member in the family of neoplasms containing the OS, and therefore we propose the term mixed epithelial and stromal tumor of the middle ear.
authors.affiliation: Department of Pathology, Faculty of Medicine in Pilsen, Charles University, Prague and Biomedical Center of the Faculty of Medicine in Pilsen, Czech Republic 30460. Electronic address: michael.michal@medima.cz.
authors.forename: Michael
authors.initials: M
authors.lastname: Michal
authors.affiliation: Department of Pathology, Faculty of Medicine in Pilsen, Charles University, Prague, Czech Republic 30460.
authors.forename: Alena
authors.initials: A
authors.lastname: Skálová
authors.affiliation: Department of Pathology, Faculty of Medicine in Pilsen, Charles University, Prague, Czech Republic 30460.
authors.forename: Dmitry V
authors.initials: DV
authors.lastname: Kazakov
authors.affiliation: Department of Pathology, Faculty of Medicine in Pilsen, Charles University, Prague, Czech Republic 30460.
authors.forename: Květoslava
authors.initials: K
authors.lastname: Pecková
authors.affiliation: Department of Radiology, Faculty of Medicine in Pilsen, Charles University, Czech Republic 30460.
authors.forename: Filip
authors.initials: F
authors.lastname: Heidenreich
authors.affiliation: Bioptical Laboratory Ltd., Pilsen, Czech Republic 32600.
authors.forename: Petr
authors.initials: P
authors.lastname: Grossmann
authors.affiliation: Department of Pathology, Faculty of Medicine in Pilsen, Charles University, Prague, Czech Republic 30460.
authors.forename: Michal
authors.initials: M
authors.lastname: Michal
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics; D001706:Biopsy; D049109:Cell Proliferation; D004428:Ear Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D004432:Ear, Middle / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D004847:Epithelial Cells / Q000737:chemistry / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D025202:Molecular Diagnostic Techniques; D018193:Neoplasms, Complex and Mixed / Q000737:chemistry / Q000235:genetics / Q000473:pathology* / Q000601:surgery; D017154:Stromal Cells / Q000737:chemistry / Q000473:pathology*; D009626:Terminology as Topic; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor
keywords: Corpus albicans like scar; Head and neck; Middle ear; Mixed epithelial and stromal tumor; Ovarian stroma