Diagnostic value of cytokeratin 7 and parvalbumin in differentiating chromophobe renal cell carcinoma from renal oncocytoma.

Abstract

Both mRNA and protein expression levels of CK7 appear significantly higher in chromophobe RCC compared to oncocytoma (p < 0.001). Parvalbumin expression is less specific but often displays a patchy pattern in oncocytomas. Our study provides further evidence that CK7 and parvalbumin immunostains may be useful in differentiating oncocytoma from chromophobe RCC in problematic cases. Negative or patchy staining (< 50% cells) for CK7 and/or parvalbumin strongly favors the diagnosis of oncocytoma.