title: A New Hitherto Unreported Histopathologic Manifestation of Mammary Analogue Secretory Carcinoma: "Masked MASC" Associated With Low-grade Mucinous Adenocarcinoma and Low-grade In Situ Carcinoma Components.
abstract: We present a salivary gland tumor of the parotid gland in a 54-year-old woman, which contained a minor mammary analogue secretory carcinoma (MASC) component (20%) intermixed with a morphologically entirely different mucinous adenocarcinomatous component that comprised 80% of the tumor mass and a morphologically nondescript low-grade intraductal carcinoma (in situ) component. On fluorescence in situ hybridization, a break in the ETV6 gene was documented in the mucinous adenocarcinomatous, the conventional MASC, and the intraductal (in situ) components. RT-PCR failed to reveal an ETV6-NTRK3 fusion. The entire conventional MASC and only rare mucinous adenocarcinoma tumor cells were mammaglobin positive, whereas the low-grade intraductal carcinoma (in-situ) component was negative. S-100 protein stained only the MASC component.
authors.affiliation: *Department of Pathology, National University Health System, Singapore, Singapore †Department of Pathology, Medical Faculty in Pilsen, Charles University in Prague, Plzen, Czech Republic.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Petersson
authors.forename: Michael
authors.initials: M
authors.lastname: Michal
authors.forename: Dmitry V
authors.initials: DV
authors.lastname: Kazakov
authors.forename: Petr
authors.initials: P
authors.lastname: Grossmann
authors.forename: Michal
authors.initials: M
authors.lastname: Michal
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D000069295:Mammary Analogue Secretory Carcinoma / Q000473:pathology*; D008875:Middle Aged; D050783:Proto-Oncogene Proteins c-ets / Q000235:genetics; D020812:Receptor, trkC / Q000235:genetics; D012097:Repressor Proteins / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000097764:ETS Translocation Variant 6 Protein
chemical_list: D050783:Proto-Oncogene Proteins c-ets; D020812:Receptor, trkC; D012097:Repressor Proteins; D000097764:ETS Translocation Variant 6 Protein