Correlation between vimentin expression and morphological features of renal cell carcinoma.

The aim of this study was to analyze the correlation between the expression of vimentin and morphological features of renal cell carcinoma (RCC). We analyzed tumor tissue of 20 patients with RCC. There were 13 female and 7 male patients with RCC confined to the kidney (pT1, pT2). They were ranging in age from 36 to 80 years (mean age 60.6 years). Thirteen tumors measured > 5 cm and 7 tumors < 5 cm in diameter. Two tumors were papillary and 18 tumors showed a non-papillary pattern. Six tumors were composed of granular cells and 14 tumors of clear cells. Formalin fixed, paraffin-embedded tumor tissue was cut at 5 microns, deparaffinized, and stained with a monoclonal antibody to vimentin (Dako, Denmark). There were 4 tumors with nuclear grade I, 3 with grade II, 11 with grade III, and 2 with grade IV. Histopathologic examination showed vimentin expression in eight cases (40%), while 12 tumors (60%) were negative. Positive reaction for vimentin was observed in all four grade I tumors, none of three grade II tumors, four of 11 grade III tumors and in none of 2 nuclear grade IV tumors. In our study, there was no statistically significant difference between the expression of vimentin and morphologic features of RCC. Our study showed the lack of correlation between the expression of vimentin and nuclear grade, cell type and histologic pattern of RCC. Further studies on a larger series of tumors as well as follow-up of patients are obviously needed.