title: Mammary analog secretory carcinoma of thyroid: A case report.
abstract: Mammary analog secretory carcinoma (MASC) is a recently described rare neoplasm that was first reported in the salivary gland with an associated ETV6-NTRK3 fusion. We present a case of MASC involving and presumably arising in the thyroid, which was originally diagnosed as papillary thyroid carcinoma on fine needle aspiration and surgical resection. The later correct diagnosis of MASC was confirmed by immunohistochemistry and molecular studies. The cytopathological features of MASC in the salivary gland are previously described; however, we present the first cytopathological description of MASC arising in the thyroid with the unique feature of prominent nuclear grooves. Differentiating MASC from overlapping features of cytopathologic mimics such as papillary thyroid carcinoma may carry crucial therapeutic implications. Diagn. Cytopathol. 2017;45:45-50. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Pathology, University of New Mexico School of Medicine, New Mexico.
authors.forename: Aaron P
authors.initials: AP
authors.lastname: Rupp
authors.affiliation: Department of Pathology, University of New Mexico School of Medicine, New Mexico.
authors.forename: Thèrése J
authors.initials: TJ
authors.lastname: Bocklage
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000235:genetics; D044963:Biopsy, Fine-Needle; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D000069295:Mammary Analogue Secretory Carcinoma / Q000235:genetics / Q000473:pathology*; D015514:Oncogene Proteins, Fusion / Q000235:genetics; D013964:Thyroid Neoplasms / Q000473:pathology*; 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
keywords: ETV6-NTRK3 fusion; MASC; cytology; mammary analog secretory carcinoma; thyroid