Sarcomatoid renal tumors differ morphologically and prognostically from other renal tumors. Using tissue microarray technology, we show that sarcomatoid renal tumors have a distinct protein expression profile for biomarkers Ki67, gelsolin and PTEN, when compared with clear-cell and papillary renal tumors. Our results confirm the previous reports that Ki67 is highly expressed in sarcomatoid tumors. We also show that gelsolin expression differs between the studied tumor types, suggesting different roles for gelsolin in the carcinogenesis of different renal tumor types.