title: Alpha-methyl CoA racemase expression in renal cell carcinomas.
abstract: Alpha-methyl CoA racemase (AMACR), a new molecular marker for prostate cancer, has been recently reported to be one of the most highly expressed genes in papillary renal cell carcinomas (RCCs). We tested the diagnostic usefulness of AMACR antibody in a series of 110 renal tumors: 53 papillary RCCs (33 type 1, 20 type 2); 25 conventional RCCs; 6 chromophobe RCCs; 9 oncocytomas; 5 mucinous tubular and spindle tumors; 2 urothelial carcinomas; 7 angiomyolipomas; and 2 Bellini carcinomas. Immunohistochemical staining was performed on formalin-fixed, paraffin-embedded tissue sections, with a primary prediluted rabbit monoclonal anti-AMACR antibody. Both type 1 and type 2 papillary RCCs exhibited cytoplasmic immunoreactivity for AMACR, with diffuse strong granular staining in 96.4% (53/55) of tumors, without correlation with type or nuclear grade. The 5 mucinous, tubular, and spindle cell carcinomas strongly expressed AMACR, and only 5 of 25 clear cell RCCs and 1 of 9 oncocytomas were focally reactive. The remaining 6 chromophobe RCCs, 5 urothelial carcinomas, and Bellini duct carcinomas showed no immunoreactivity for AMACR. Because high expression of AMACR is found in papillary RCCs (type 1 and 2) and in mucinous, tubular, and spindle cell carcinomas of the kidney, immunostaining for AMACR should be used in conjunction with other markers when histological typing of a renal tumor is difficult.
authors.affiliation: Department of Pathology, Hôpital Saint Joseph, 75014 Paris Cedex, France. vmolinie@hopital-saint-joseph.org
authors.forename: Vincent
authors.initials: V
authors.lastname: Molinié
authors.forename: André
authors.initials: A
authors.lastname: Balaton
authors.forename: Samuel
authors.initials: S
authors.lastname: Rotman
authors.forename: Douha
authors.initials: D
authors.lastname: Mansouri
authors.forename: Isabelle
authors.initials: I
authors.lastname: De Pinieux
authors.forename: Toufik
authors.initials: T
authors.lastname: Homsi
authors.forename: Louis
authors.initials: L
authors.lastname: Guillou
mesh_terms: D002288:Adenocarcinoma, Mucinous / Q000201:enzymology / Q000473:pathology; D018249:Adenoma, Oxyphilic / Q000201:enzymology / Q000473:pathology; D002291:Carcinoma, Papillary / Q000201:enzymology / Q000473:pathology; D002292:Carcinoma, Renal Cell / Q000201:enzymology* / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D007680:Kidney Neoplasms / Q000201:enzymology* / Q000473:pathology*; D019998:Racemases and Epimerases / Q000235:genetics / Q000378:metabolism*
chemical_list: D019998:Racemases and Epimerases; C108352:alpha-methylacyl-CoA racemase