title: PAX8 and PAX2 immunostaining facilitates the diagnosis of primary epithelial neoplasms of the male genital tract.
abstract: PAX8 and PAX2 are cell-lineage-specific transcription factors that are essential for the development of Wolffian and Müllerian ducts and have recently emerged as specific diagnostic markers for tumors of renal or Müllerian origin. Little is known about their expression in the Wolffian duct-derived human male genital tract. We report our findings of PAX8 and PAX2 expression in the epithelium of the normal male genital tract and in epithelial tumors derived therefrom using immunohistochemistry (IHC). We found that PAX8 and PAX2 were expressed in the epithelium of the male genital tract from the rete testis to the ejaculatory duct. Rare glands in the prostatic central zone, a tissue of purported Wolffian duct origin, were focally positive for PAX2, but no PAX8 was detected in this area, a finding that may warrant further study. We found diffuse expression of PAX8 and PAX2 in 1 case each of serous cystadenoma of the epididymis, carcinoma of the rete testis, Wolffian adnexal tumor of the seminal vesicle, and endometrioid carcinoma of the seminal vesicle. Neither PAX8 nor PAX2 was detected in the seminiferous tubules and interstitium of the normal testis, nor in Leydig cell tumors (n=6), Sertoli cell tumors (n=2), or 48 of 49 germ cell tumors. One pediatric yolk sac tumor showed focal and weak staining for PAX8. Tumors of mesothelial origin, that is, adenomatoid tumors (n=3) and peritoneal malignant mesotheliomas (n=37) in men, were negative for PAX2 and PAX8. Neither PAX2 nor PAX8 was present in other areas of the prostate. Expression of PAX8 and PAX2 in these primary epithelial neoplasms of the male genital tract is due to their histogenetic relationship with Wolffian or Müllerian ducts. PAX8 and PAX2 IHC may facilitate the diagnosis of these tumors and should be included in the differential diagnostic IHC panel.
authors.affiliation: Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA. gt2125@columbia.edu
authors.forename: Guo-Xia
authors.initials: GX
authors.lastname: Tong
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Memeo
authors.forename: Cristina
authors.initials: C
authors.lastname: Colarossi
authors.forename: Diane
authors.initials: D
authors.lastname: Hamele-Bena
authors.forename: Cristina
authors.initials: C
authors.lastname: Magi-Galluzzi
authors.forename: Ming
authors.initials: M
authors.lastname: Zhou
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Lagana
authors.forename: Lara
authors.initials: L
authors.lastname: Harik
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Oliver-Krasinski
authors.forename: Mahesh
authors.initials: M
authors.lastname: Mansukhani
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Falcone
authors.forename: Hanina
authors.initials: H
authors.lastname: Hibshoosh
authors.forename: Kathleen
authors.initials: K
authors.lastname: O'Toole
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D004847:Epithelial Cells / Q000378:metabolism / Q000473:pathology; D005834:Genital Neoplasms, Male / Q000175:diagnosis* / Q000378:metabolism; D005837:Genitalia, Male / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D009095:Mullerian Ducts / Q000033:anatomy & histology / Q000378:metabolism; D051762:PAX2 Transcription Factor / Q000378:metabolism*; D000072636:PAX8 Transcription Factor; D051761:Paired Box Transcription Factors / Q000378:metabolism*; D014928:Wolffian Ducts / Q000033:anatomy & histology / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D051762:PAX2 Transcription Factor; C497318:PAX2 protein, human; D000072636:PAX8 Transcription Factor; C083325:PAX8 protein, human; D051761:Paired Box Transcription Factors