[CLINICAL CONSIDERATION OF PERCUTANEOUS RENAL BIOPSY FOR ADVANCED RENAL TUMOR]

(Objective) Advanced renal tumors are often difficult to diagnose based on radiological findings. The preset study aimed to evaluate the diagnostic efficacy and safety of percutaneous renal tumor biopsy in patients with advanced renal tumors. (Methods) Thirteen patients (6 males and 7 females) with advanced renal tumors who underwent percutaneous renal tumor biopsy between January 2015 and May 2017 were reviewed retrospectively. (Results) The median patients age was 69 years (range=40-81 years). The median renal tumor size was 91 mm (53-195 mm). Four cases were diagnosed as clear cell renal cell carcinoma (CCRCC), 8 as non-CCRCC, and 1 as malignant lymphoma prior to biopsy. Histopathological diagnoses after biopsy were CCRCC in 3, urothelial carcinoma in 3, and papillary renal cell carcinoma in 2 cases; there was 1 case each of chromophobe renal cell carcinoma, spindle cell RCC, carcinoma of the collecting ducts of Bellini, and nephroblastoma. Diagnosis could not be made in 1 case due to sampling error. Adverse events developed after renal tumor biopsy, with microscopic hematuria in 2 and pyrexia in 1 case. These were Grade 1 events according to the Clavien-Dindo Classification. Disseminated tumors were not observed during the follow-up period. (Conclusion) Percutaneous tumor biopsy for patients with advanced renal tumor is a safe procedure and useful for confirming the diagnosis pathologically before starting medication.