title: Cdx2, cytokeratin 20, thyroid transcription factor 1, and prostate-specific antigen expression in unusual subtypes of prostate cancer.
abstract: There are some unusual histologic variants of prostate carcinoma, including mucinous, signet-ring cells, and ductal carcinomas that can metastasize in a problematic way and simulate lung, colorectal, or bladder primaries. Currently, antibodies that are organ-specific have been used in the routine surgical pathology practice. Our aim is to study the profile of expression of Cdx2, thyroid transcription factor 1 (TTF1), and cytokeratin 20 (CK20) in prostate cancer with unusual histologic finding. Twenty-nine prostate adenocarcinomas with unusual histologic findings were submitted to immunohistochemistry with prostate-specific antigen (PSA), CK20, Cdx2, and TTF1 antibodies. There were 7 mucinous, 5 ductal, 2 signet-ring cells, and 15 usual acinar adenocarcinomas with focal mucinous differentiation. To compare the results with usual acinar adenocarcinomas, we studied 10 primary and their respective lymph node metastases in a tissue microarray, 2 unusual metastatic adenocarcinomas, and 6 usual acinar high-grade carcinomas. For tumors with special histologic finding, Cdx2 was expressed by 9 (31.0%) mucinous, signet-cell, or with focal mucinous differentiation. Thyroid transcription factor 1 was moderately positive in mucinous differentiation areas of 2 (6.9%) adenocarcinomas. Cytokeratin 20 was expressed by 9 (31.0%) tumors, among them, 3 ductal adenocarcinomas. Prostate-specific antigen was positive in 28 (96.6%) cases and negative in 1 ductal adenocarcinoma. There was only 1 worrisome ductal adenocarcinoma that was strongly CK20 positive and PSA negative. Almost one third of mucinous prostate carcinomas express Cdx2. Cytokeratin 20 can be positive also in one third of prostate carcinomas, especially the ductal type. Pathologist should be alert when evaluating immunohistochemical profiles of unusual histologic findings of prostate cancer, mostly in distant sites.
authors.affiliation: Laboratory of Surgical and Molecular Pathology, Hospital Sirio Libanes, São Paulo 01308-050, Brazil; Laboratory of Medical Investigation, Urology-LIM 55, Medical School USP, São Paulo 01246-903, Brazil. Electronic address: katiaramos@uol.com.br.
authors.forename: Katia Ramos Moreira
authors.initials: KRM
authors.lastname: Leite
authors.affiliation: Laboratory of Surgical and Molecular Pathology, Hospital Sirio Libanes, São Paulo 01308-050, Brazil.
authors.forename: Cristina A T S
authors.initials: CATS
authors.lastname: Mitteldorf
authors.affiliation: Laboratory of Medical Investigation, Urology-LIM 55, Medical School USP, São Paulo 01246-903, Brazil.
authors.forename: Miguel
authors.initials: M
authors.lastname: Srougi
authors.affiliation: Laboratory of Medical Investigation, Urology-LIM 55, Medical School USP, São Paulo 01246-903, Brazil.
authors.forename: Marcos F
authors.initials: MF
authors.lastname: Dall'Oglio
authors.affiliation: Laboratory of Medical Investigation, Urology-LIM 55, Medical School USP, São Paulo 01246-903, Brazil.
authors.forename: Alberto A
authors.initials: AA
authors.lastname: Antunes
authors.affiliation: Laboratory of Medical Investigation, Urology-LIM 55, Medical School USP, São Paulo 01246-903, Brazil.
authors.forename: José
authors.initials: J
authors.lastname: Pontes
authors.affiliation: Laboratory of Surgical and Molecular Pathology, Hospital Sirio Libanes, São Paulo 01308-050, Brazil.
authors.forename: Luiz Heraldo
authors.initials: LH
authors.lastname: Camara-Lopes
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D000071616:CDX2 Transcription Factor; D015870:Gene Expression; D018398:Homeodomain Proteins / Q000096:biosynthesis*; D006801:Humans; D007150:Immunohistochemistry; D053554:Keratin-20 / Q000378:metabolism; D008297:Male; D009687:Nuclear Proteins / Q000096:biosynthesis*; D017430:Prostate-Specific Antigen / Q000096:biosynthesis*; D011471:Prostatic Neoplasms / Q000378:metabolism* / Q000473:pathology; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000096:biosynthesis*
chemical_list: D000071616:CDX2 Transcription Factor; C491270:CDX2 protein, human; D018398:Homeodomain Proteins; C507499:KRT20 protein, human; D053554:Keratin-20; C000614412:NKX2-1 protein, human; D009687:Nuclear Proteins; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors; D017430:Prostate-Specific Antigen