Immunohistochemical expression of p53 and bcl-2 proteins is not associatedwith sarcomatoid change in renal cell carcinoma

An immunhistochemical study was conducted to examine the expression of p53 and bcl-2 proteins in RCC (renal cell carcinoma) with sarcomatoid change in order to determine whether abnormalities in those proteins are associated with an enhanced malignant potential of RCC. Paraffin-embedded tissues from 11 patients with RCC, in which sarcomatoid change was prominent, were stai ned using anti-p53, bcl-2 and Ki-67 antibodies. Immunoreactivities for thes e antibodies were compared between the sarcomatoid components and correspon ding basic histologic (clear or papillary) components in individual cases. Measurement of the mean nuclear areas of each component was also performed using an image analyzer system. There was no substantial increase in immuno reactivity for p53 or bcl-2 proteins in sarcomatoid components as compared with basic components. In contrast, the percentage of Ki-67-positive cells and the mean nuclear area were significantly larger in sarcomatous componen ts than in basic components The expression of p53 and bcl-2 proteins was no t likely to play a major role in the sarcomatoid change of RCC.