title: S100A4 protein and mesothelin expression in dysplasia and carcinoma of the extrahepatic bile duct.
abstract: We evaluated the expression of S100A4 protein and mesothelin in dysplasia and carcinoma of the extrahepatic bile duct (EBD) and their potential use as adjuncts for differentiating carcinomatous and significant high-grade dysplastic epithelium from reactive or inflammatory glandular atypia of the EBD. We used immunohistochemical analysis on formalin-fixed tissue sections from 10 cases of carcinoma, 6 cases of high-grade dysphasia (HGD), 4 cases of low-grade dysplasia (LGD), and 10 cases of benign or reactive or inflammatory epithelium from the EBD. Expression of S100A4 protein was observed in 8 invasive carcinomas (80%), 5 HGD/carcinoma in situ cases (83%), and 0 LGDs. Mesothelin was expressed in 5 (50%) of 10 adenocarcinomas, 1 (17%) of 6 HGD/adenocarcinoma in situ cases, and 0 LGDs. No case of normal or reactive epithelium was positive for S100A4 protein or mesothelin. Mesothelin has moderate sensitivity and high specificity, whereas S100A4 protein is sensitive and specific for the identification of carcinoma and HGD of the EBD. S100A4 protein alone or combined with mesothelin can be used as an adjunct in differentiating carcinomatous and significant high-grade dysplastic epithelium from LGD and reactive or inflammatory glandular atypia of the EBD.
authors.affiliation: Department of Pathology and Laboratory Medicine, Hartford Hospital, Hartford, CT 06102, USA.
authors.forename: Huicong
authors.initials: H
authors.lastname: Zhao
authors.forename: Larisa
authors.initials: L
authors.lastname: Davydova
authors.forename: Daniza
authors.initials: D
authors.lastname: Mandich
authors.forename: Richard W
authors.initials: RW
authors.lastname: Cartun
authors.forename: Saverio
authors.initials: S
authors.lastname: Ligato
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology; D001650:Bile Duct Neoplasms / Q000378:metabolism / Q000473:pathology*; D017734:Bile Ducts, Extrahepatic / Q000378:metabolism / Q000473:pathology*; D002278:Carcinoma in Situ / Q000378:metabolism / Q000473:pathology; D004848:Epithelium / Q000737:chemistry / Q000473:pathology; D058851:GPI-Linked Proteins; D006801:Humans; D007150:Immunohistochemistry; D008562:Membrane Glycoproteins / Q000096:biosynthesis*; D000090204:Mesothelin; D009361:Neoplasm Invasiveness; D000071999:S100 Calcium-Binding Protein A4; D009418:S100 Proteins / Q000096:biosynthesis*
chemical_list: D058851:GPI-Linked Proteins; D008562:Membrane Glycoproteins; D000071999:S100 Calcium-Binding Protein A4; D009418:S100 Proteins; C077591:S100A4 protein, human; D000090204:Mesothelin