[Percutaneous biopsy of the renal masses under ultrasound: a single-center 14 years experience].

OBJECTIVE: To assess the diagnostic rate, safety and clinical application of percutaneous renal masses biopsy for advanced renal cell carcinoma patients. METHODS: In this retrospective study, we collected the data of renal masses from the patients who underwent renal masses biopsy under ultrasound from April 2001 to December 2014 in Peking University First Hospital. A total of 75 patients who were undiagnosed or diagnosed with advanced renal cell carcinoma by the imageological method were enrolled in this study. The patient and lesion characteristics such as tumor size, pathology of tumor, histologic subtype, pathological grade, biopsied location and biopsied cores were recorded and analyzed. RESULTS: Among all the 75 patients, biopsy was diagnostic in 64 cases (85.3%) and non-diagnostic in 11 cases (14.7%). Of the 64 diagnostic biopsies, 60 were malignant, including 37 (61.7%) renal cell carcinoma (RCC), 13 (21.7%) urothelial carcinoma and 10 (16.7%) other malignant masses. Of all the RCC subjects, 24 suffered from clear cell RCC, 5 papillary RCC, 3 collecting duct carcinomas, 1 unclassified RCC and 4 unknown subtypes. The 11 non-diagnostic biopsied samplings included inflammatory, blood and extrarenal tissue and normal renal tissue. The proportion of collecting duct carcinoma in RCC was 10.8% and the proportion of squamous carcinoma in urothelial carcinoma was 23.1%, which were both higher than the previous research findings. For the male and female groups, non-diagnostic yields were 6.5% and 30.4%, respectively (P=0.022). Of all the 75 patients, 13 renal cell carcinoma patients underwent the surgical treatment and got the results of postoperative pathology. Comparing preoperative biopsy pathological diagnosis with postoperative pathological diagnosis, we found the diagnostic correct rates for benign and malignant lesions, pathological subtype and pathological grade were 100%, 81.8% and 60%, respectively. Mild macroscopic hematuria occurred in 1 case after RMB and there were no serious complications in all the cases. CONCLUSION: Percutaneous renal masses biopsy under ultrasound with a high diagnostic rate which can define the histologic subtype of renal cell carcinoma. With targeted therapy, more and more patients whose evaluation suggests local advanced disease or metastatic tumors adopt renal tumor biopsy to define the histologic subtype, which could avoid unnecessary surgical treatment.