Expression of S-100 protein in renal cell neoplasms.
Polyclonal antibody to S-100 protein has been routinely applied for initial screening of various types of tumors, including, melanocytic tumors and neurogenic tumors. S-100 protein has been shown to have a broad distribution in human tissues, including renal tubules. The potential utility of S-100 protein in renal cell neoplasms has not been extensively investigated. Using an EnVision-Horseradish Peroxidase (HRP; Dako, Carpinteria, Calif) kit, we evaluated the diagnostic value of S-100 protein on tissue microarray sections from 175 cases of renal epithelial neoplasm (145 primary renal neoplasms and 30 metastatic renal cell carcinomas) and 24 non-neoplastic renal tissues. Immunohistochemical stains for pancytokeratin, HMB-45, and Mart-1 were also performed. Western blot using the same antibody (anti-S-100 protein) was performed on 10 cases of renal cell neoplasm. The results demonstrated that nuclear and cytoplasmic staining pattern for S-100 protein was observed in 56 (69%) of 81 conventional (clear cell) renal cell carcinomas (RCCs), 10 (30%) of 33 papillary RCCs, 1 (6%) of 16 ChRCCs, and 13 (87%) of 15 oncocytomas. Among the 81 cases of CRCC, positivity for S-100 protein was seen in 41 (71%) of 58 and 15 (65%) of 23 cases with Furhman nuclear grade I/II and III/IV, respectively. Focal immunostaining was present in 22 (92%) of 24 normal renal tubules. Similar staining pattern was observed in 21 (70%) of 30 metastatic RCCs. Western blotting demonstrated the S-100 protein expression in both renal cell neoplasm and normal renal tissue. Overexpression of S-100 in oncocytomas compared with ChRCCs was confirmed by the data of Western blot and cDNA microarray analysis. Importantly, 14.8% (12/81) of clear cell RCC and 13.3% (4/30) of metastatic RCC revealed an immunostaining profile of pancytokeratin (-)/S-100 protein (+). These data indicate that caution should be taken in interpreting an unknown primary with S-100 positivity and cytokeratin negativity. In addition, it suggests that S-100 has a diagnostic value in differentiating oncocytoma from ChRCC.
Lin
Fan
F
Department of Laboratory Medicine, Geisinger Medical Center, Danville, PA 17822, USA.
Yang
Wannian
W
Betten
Mark
M
Teh
Bin Tean
BT
Yang
Ximing J
XJ
D018249:Adenoma, Oxyphilic / Q000175:diagnosis / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism; D015153:Blotting, Western; D002292:Carcinoma, Renal Cell / Q000175:diagnosis / Q000378:metabolism* / Q000556:secondary; D002467:Cell Nucleus / Q000378:metabolism / Q000473:pathology; D003593:Cytoplasm / Q000378:metabolism / Q000473:pathology; D003937:Diagnosis, Differential; D006801:Humans; D007124:Immunoenzyme Techniques; D007668:Kidney / Q000033:anatomy & histology / Q000378:metabolism / Q000473:pathology; D007680:Kidney Neoplasms / Q000378:metabolism* / Q000473:pathology; D009367:Neoplasm Staging; D009418:S100 Proteins / Q000378:metabolism*; D046888:Tissue Array Analysis
D014408:Biomarkers, Tumor; D009418:S100 Proteins