Hedieh Moradi-Tabriz - Department of Pathology, Sina hospital, Tehran University of Medical Sciences, Tehran, Iran
Dorna Motevalli - Department of Pathology, Sina hospital, Tehran University of Medical Sciences, Tehran, Iran
Maliheh Naghavi - Department of Pathology, Sina hospital, Tehran University of Medical Sciences, Tehran, Iran

Concurrence presence of separated Renal Cell Carcinoma and oncocytoma is very rare, although hybrid renal cell carcinoma and oncocytoma are reported in some studies.Herein, we report a 68 year-old man who presented with flank pain, frequency, nocturia and dysuria, radiologic workup revealed a hypoechoic mass measuring 52*53 mm in lower pole and a cortical mass measuring 31 mm in middle part of the right kidney. Right radical nephrectomy was done for the patient and specimen sent to Anatomical Pathology Lab, Sina Hospital, Tehran, Iran. On gross examination, right kidney and perirenal fat measuring 14*11*6 cm, on cutting a whitish tumoral lesion which was measuring 4*3*2 cm in upper pole and a well-circumscribed brownish lesion measuring 5.5*5*3 cm was seen in lower pole. On microscopic examination, the upper pole mass showed neoplastic cells having clear abundant cytoplasm arranged in nests with intervening blood vessels diagnosed as a renal cell carcinoma with nuclear grade 3, and lower pole mass was a renal oncocytoma which showed polygonal cells with abundant granular eosinophilic cytoplasm arranged in nests. Nuclei were uniform and round without significant pleomorphism. Both the tumors were limited to kidney and surgical margins were free from tumor. Burger et al. reported metachronous multifocal renal oncocytoma with contralateral chromophobe renal cell carcinoma and one case of bilateral oncocytomas and the author evaluated chromosomal abnormalities in the mentioned tumors all 4 tumors had loss of genetic material on chromosome 1p and one of them had an additional loss of chromosome 10. Paplani et al. reported a young patient with bilateral hybrid oncocytoma and renal cell carcinoma. Unilateral separated oncocytoma and renal cell carcinoma is very rare and less than 3 cases have been reported in the literature. Although hybrid renal cell carcinoma and oncocytoma have reported more frequently.

renal cell carcinoma, oncocytoma