title: The diagnostic role of claudins in serous effusions.
abstract: We analyzed the diagnostic role of claudins in effusion cytology in 325 effusions, including 218 ovarian, 49 breast, 15 cervical or endometrial, 10 gastrointestinal, and 8 lung adenocarcinomas and 25 malignant mesotheliomas (MMs). Specimens were analyzed for claudin-1 and claudin-3 expression using immunohistochemical analysis. Ovarian and breast adenocarcinoma were further analyzed for claudin-7 expression. Claudin-1 expression was most frequent in ovarian and cervical or endometrial adenocarcinoma compared with other adenocarcinomas and MMs (P < .001). Claudin-3 expression was comparable in adenocarcinomas of different origin but was absent in MMs (P < .001). Reactive mesothelial cells rarely expressed claudins. Claudin-7 expression was higher in ovarian than in breast adenocarcinoma (P < .001). Our data suggest that expression of claudin-3 or claudin-7 is specific for adenocarcinoma and rules out the diagnosis of cells as mesothelial and that absence of claudin-1 expression excludes ovarian carcinoma as the possible origin of metastatic adenocarcinoma. Claudins may, therefore, be of diagnostic value in effusion cytology.
authors.affiliation: Pathology Clinic, Rikshospitalet-Radiumhospitalet Medical Center, University of Oslo, Oslo, Norway.
authors.forename: Lilach
authors.initials: L
authors.lastname: Kleinberg
authors.forename: Arild
authors.initials: A
authors.lastname: Holth
authors.forename: Eduard
authors.initials: E
authors.lastname: Fridman
authors.forename: Ignat
authors.initials: I
authors.lastname: Schwartz
authors.forename: Ie-Ming
authors.initials: IeM
authors.lastname: Shih
authors.forename: Ben
authors.initials: B
authors.lastname: Davidson
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000378:metabolism / Q000556:secondary; D001202:Ascitic Fluid / Q000378:metabolism / Q000473:pathology*; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000175:diagnosis / Q000378:metabolism; D062445:Claudin-1; D062465:Claudin-3; D057167:Claudins; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000175:diagnosis / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism*; D008654:Mesothelioma / Q000175:diagnosis / Q000378:metabolism; D010051:Ovarian Neoplasms / Q000175:diagnosis / Q000378:metabolism; D016066:Pleural Effusion, Malignant / Q000175:diagnosis* / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; C568108:CLDN1 protein, human; C568122:CLDN3 protein, human; C473255:CLDN7 protein, human; D062445:Claudin-1; D062465:Claudin-3; D057167:Claudins; D008565:Membrane Proteins