Immunohistochemical analysis of 6 cases of renal angiomyolipoma not related to tuberous sclero- sis proved the same rate of expression of HMB 45 and NKI/C3 as well in epithelioid smooth muscle cells of the tumours. Beyond this, an unspecific expression of a1-antitrypsin and a1-antichymot- rypsin was found which has not been mentioned in the literature up to now.

        Key words: renal angiomyolipoma - immunohistochemistry - HMB 45 - NKI/C3 - a1 antitrypsin - a1 antichymotrypsin