[Two cases of renal oncocytoma]

Two cases of renal oncocytoma are reported. These patients were a 67-year-old man and a 74-year-old man who had incidentally been indicated to have a right renal mass lesion by echography in other hospitals. In both cases, enhanced computed tomographic scan showed a low density renal mass. In selective renal angiogram of the two cases, a spoke-wheel configuration of vessels could be seen in one case, but there was no evidence of renal mass in another. Total nephrectomy was performed in each case. Two masses were pathologically diagnosed as oncocytoma, constructed of large eosinophilic cells with granular cytoplasm and small regular nuclei. These two patients have been well for more than 2 years after the surgery. These are the 25th and 26th cases of renal oncocytoma reported in Japan before December, 1988.