[Retrospective study of diagnosis and treatment of renal oncocytoma]

To summarize the experience of diagnosis and surgical treatment of renal oncocytoma, and to evaluate the surgical results based on follow-up results, in order to find the best strategy.

In the study, 21 cases with renal oncocytoma from December 2003 to April 2016 in Peking University Third Hospital were retrospectively analyzed, including 4 males, and 17 females, with 10 cases on the right side and 11 cases on the left side. Their age was between 15 to 80 years (average: 58 years). Ultrasound or CT examination after admission was conducted. Ultrasound examination showed solid nodules. CT manifestations were solid masses with enhancement, and the tumor size was between 1.5 cm to 6.5 cm (average: 3.3 cm). Of the 21 cases, 9 were located in the middle of kidney, 7 were located in the upper pole, and 5 were located in the lower pole. After preoperative examination, according to the size and location of the tumor, laparoscopic partial nephrectomy or laparoscopic nephrectomy was performed, respectively.

All the operations were successful, in which 17 cases underwent laparoscopic partial nephrectomy (including 3 cases which were converted to open surgery), and 4 cases underwent laparoscopic radical nephrectomy. The operation time ranged from 75 to 274 min (mean: 144 min), and the blood loss ranged from 10 to 1 000 mL (mean: 115 mL). The postoperative hospital stay time ranged from 6 to 13 d (average: 8.2 d). The pathological results were all renal oncocytoma. In the study, 17 cases were followed up while 4 cases were lost to follow-up. The follow-up time ranged from 12 to 175 months (mean: 44 months). One case died in 20 months after operation with unknown reason, and there were no recurrence or metastasis in the other 16 cases.

Renal oncocytoma is a benign tumor with good prognosis. Enhanced CT is an effective diagnostic method in assistant examination, but it is difficult to differentiate clear cell carcinoma only from the naked eye. It is worthwhile to measure CT value at different stages of the tumor by picture archiving and communication systems (PACS), and to compare with CT value of adjacent kidney tissue may improve the diagnostic efficiency of CT. Laparoscopic surgery is an effective treatment for renal oncocytoma. We recommend laparoscopic partial nephrectomy for the patients with renal oncocytoma as the best choice if conditions permit.