title: Papillary-cystic pattern is characteristic in mammary analogue secretory carcinomas but is rarely observed in acinic cell carcinomas of the salivary gland.
abstract: Mammary analogue secretory carcinoma (MASC) has a specific ETV6-NTRK3 translocation and morphologically overlaps with acinic cell carcinoma (AciCC). Before the recognition of MASC, in AciCC, four histologic patterns were identified including microcystic, solid, papillary-cystic, and follicular. The aim of this study was to evaluate histologic patterns in these two neoplasms through comprehensive histologic subtyping. Using fluorescence in situ hybridization (FISH), we identified 14 cases of MASC and 21 cases of AciCC. We used comprehensive histologic subtyping to provide a semiquantitive assessment of histologic patterns in each tumor and performed immunohistochemical analyses including S100/vimentin/mammaglobin/DOG1. MASC often presented papillary-cystic patterns without a solid component, previously considered to be one of the four major patterns associated with AciCC. However, in our study, this histologic feature was rarely seen in AciCC and more characteristic of MASC. In aspiration cytology samples, MASC was associated with more cellular atypia. An immunohistochemical panel of S100/mammaglobin/DOG1 was found useful for differential diagnosis. Comprehensive subtyping of histologic patterns is a useful screening method prior to initiation of molecular testing.
authors.affiliation: Department of Pathology, National Taiwan University Hospital and National Taiwan University College of Medicine, No 7, Chung-Shan South Road, 100, Taipei, Taiwan.
authors.forename: Min-Shu
authors.initials: MS
authors.lastname: Hsieh
authors.forename: Yueh-Hung
authors.initials: YH
authors.lastname: Chou
authors.forename: Shin-Joe
authors.initials: SJ
authors.lastname: Yeh
authors.forename: Yih-Leong
authors.initials: YL
authors.lastname: Chang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000032:analysis*; D018267:Carcinoma, Acinar Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D016133:Polymerase Chain Reaction; D012468:Salivary Gland Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D055815:Young Adult; D020812:Receptor, trkC; D000097764:ETS Translocation Variant 6 Protein
chemical_list: D014408:Biomarkers, Tumor; D015514:Oncogene Proteins, Fusion; C484319:ETV6-NTRK3 fusion protein, human; D020812:Receptor, trkC; D000097764:ETS Translocation Variant 6 Protein