title: Mammary analogue secretory carcinoma of salivary glands: a clinicopathologic and molecular study including 2 cases harboring ETV6-X fusion.
abstract: Mammary analogue secretory carcinoma (MASC) is a recently described low-grade carcinoma with morphologic and genetic similarity, including ETV6-NTRK3 fusion, to secretory carcinoma of the breast. ETV6 is frequently involved in other epithelial and nonepithelial tumors, and many fusion partners of ETV6 have been reported. In the present study, 14 Japanese MASC cases were clinicopathologically and molecularly analyzed. The median age of the patients was 39 years, and the male:female ratio was 6:8. All cases showed histopathologic findings compatible with those previously described for MASC and harbored an ETV6 split as visualized by fluorescence in situ hybridization. Two cases showed thick fibrous septa and invasive features including vascular or perineural tumor involvement, findings that are rare in MASC. In addition, in these 2 cases, non-NTRK3 genes appeared to fuse with ETV6 (ETV6-X fusion). NTRK1 and NTRK2, both members of the NTRK family, were not involved. Of the 14 MASC cases, the ETV6-NTRK3 fusion transcript was positive in 6 cases, and the relative expression level of the ETV6-NTRK3 fusion transcript was variable, ranging from 1 to 5.8. Results of the present study of MASC suggest that (1) ETV6 occasionally fuses with unknown non-NTRK3 genes, (2) ETV6-X cases might have an invasive histology, (3) for molecular diagnosis of MASC, fluorescence in situ hybridization to detect ETV6 splits is the method of choice, and (4) the expression level of the ETV6-NTRK3 fusion transcript is considerably variable. These findings provide a novel insight into the oncogenesis, histopathology, diagnosis, treatment, and prognosis of this newly recognized carcinoma.
authors: Departments of *Pathology and Molecular Diagnostics ‡Otorhinolaryngology, Head and Neck Surgery, Nagoya City University Graduate School of Medical Sciences †Department of Maxillofacial Surgery, Aichi-Gakuin University School of Dentistry, Nagoya §Department of Diagnostic Pathology, Kochi Health Sciences Center, Kochi ∥Department of Anatomic Pathology, Tokyo Medical University, Tokyo, Japan.
authors: Yohei
authors: Y
authors: Ito
authors: Kenichiro
authors: K
authors: Ishibashi
authors: Ayako
authors: A
authors: Masaki
authors: Kana
authors: K
authors: Fujii
authors: Yukio
authors: Y
authors: Fujiyoshi
authors: Hideo
authors: H
authors: Hattori
authors: Daisuke
authors: D
authors: Kawakita
authors: Manabu
authors: M
authors: Matsumoto
authors: Satoru
authors: S
authors: Miyabe
authors: Kazuo
authors: K
authors: Shimozato
authors: Toshitaka
authors: T
authors: Nagao
authors: Hiroshi
authors: H
authors: Inagaki
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000235:genetics* / Q000473:pathology*; D002648:Child; 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; D050783:Proto-Oncogene Proteins c-ets / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics*; D012468:Salivary Gland Neoplasms / Q000235:genetics* / Q000473:pathology*; D055815:Young Adult; D000097764:ETS Translocation Variant 6 Protein
chemical_list: D015514:Oncogene Proteins, Fusion; D050783:Proto-Oncogene Proteins c-ets; D012097:Repressor Proteins; D000097764:ETS Translocation Variant 6 Protein