title: Evaluation of putative renal cell carcinoma markers PAX-2, PAX-8, and hKIM-1 in germ cell tumors: a tissue microarray study of 100 cases.
abstract: In a subset of cases, metastatic renal cell carcinoma can demonstrate significant morphologic overlap with germ cell neoplasms, making accurate diagnosis challenging. In such cases, immunohistochemistry is often used as an adjunct diagnostic tool. Expression of the putative renal cell carcinoma markers PAX-2, PAX-8, and hKIM-1 has been reported in a small series of certain germ cell tumors, raising doubt about their specificity for renal cell carcinoma. To further characterize these markers, we evaluated PAX-2, PAX-8, and hKIM-1 staining in 100 germ cell tumors using tissue microarrays. PAX-2 and PAX-8 staining was identified in 50% and 25% of yolk sac tumors (respectively), with hKIM-1 staining identified in 48% of embryonal carcinomas and 50% of yolk sac tumors. All other germ tumor cells (notably including 62 seminomas) were negative for all 3 markers, in contrast to prior reports of PAX-8 reactivity in seminoma. This study indicates that PAX-2, PAX-8, and hKIM-1 should be used cautiously in distinguishing renal cell carcinoma from nonseminomatous germ cell neoplasia and also adds to the growing list of nonrenal tumors that express these 3 markers.
authors.affiliation: Department of Pathology, Stanford University, Stanford, CA, USA. asangoi2@yahoo.com
authors.forename: Ankur R
authors.initials: AR
authors.lastname: Sangoi
authors.forename: Jesse K
authors.initials: JK
authors.lastname: McKenney
authors.forename: James D
authors.initials: JD
authors.lastname: Brooks
authors.forename: Joseph V
authors.initials: JV
authors.lastname: Bonventre
authors.forename: John P
authors.initials: JP
authors.lastname: Higgins
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism*; D002292:Carcinoma, Renal Cell / Q000175:diagnosis* / Q000378:metabolism; D003937:Diagnosis, Differential; D018240:Endodermal Sinus Tumor / Q000175:diagnosis* / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D000072596:Hepatitis A Virus Cellular Receptor 1; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000175:diagnosis* / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000378:metabolism*; D009373:Neoplasms, Germ Cell and Embryonal / Q000175:diagnosis* / Q000378:metabolism; D051762:PAX2 Transcription Factor / Q000378:metabolism*; D000072636:PAX8 Transcription Factor; D051761:Paired Box Transcription Factors / Q000378:metabolism*; D011991:Receptors, Virus / Q000378:metabolism*; D012680:Sensitivity and Specificity; D046888:Tissue Array Analysis
chemical_list: D014408:Biomarkers, Tumor; C491143:HAVCR1 protein, human; D000072596:Hepatitis A Virus Cellular Receptor 1; D008562:Membrane Glycoproteins; D051762:PAX2 Transcription Factor; C497318:PAX2 protein, human; D000072636:PAX8 Transcription Factor; C083325:PAX8 protein, human; D051761:Paired Box Transcription Factors; D011991:Receptors, Virus