Renal ce ll careina ma is the most comman tumor of the kidney. Angiomyalıpoma is relatively uncommon mesenchymal tumor composed of varying admixture ofmature adipose tissue, smooth muscle, and blood vessels. Even more uncommon is the simultaneous occurence of the se two tumors in the same kidney. When each tumors are found individually in a significiant kidney, than usually clinical, radiological, histopathological diagnosis and treatment are possible. But if simultaneous occurence of the two dif.fernt tumors are see n, important dif.ferantial diagnostic problems might occur. Our report is about a 58 years-o/d woman. She· was thought to have renal cell carcinoma. Subsequent computer tomography demonstrated a mass that 3 cm in diameter. in the left kidney (First prediagnosis is renal cell carcinoma). There was anather mass which contaıns lipid, 4 cm in diameter, 2 cm beneath the tumor we talked abought. When histopathology and convansional-immunhistochemicl stains are assesed together, malign turnar was renal cell carcinoma. The other turnar was angiomyolipoma. In our report, smooth muscle component of angiomyolipoma was much apparent. Because of wide-spread spindled myoid cells and epitheloid cells, distinguishing from renal cell carcinoma was difficult. Interestingly immunhistochemical studies have shown that angiomyolipoma, focally, expressed HMB45, Melanl and CD117.

Keywords: Tuberous Sclerosis, Angiomyolipoma, Reral eel/ corcinoma