[Clinical consideration of percutaneous renal biopsy for renal tumor].

We performed ultrasound-guided biopsies on 14 patients having tumors that were difficult to distinguish as benign or malignant on computed tomography. The study took place from January 2004 to December 2011. Of the 14 tumors biopsied, 12 were malignant, 1 was benign, and 1 was a sampling error. Of the 12 malignant tumors, 7 were primary kidney carcinomas. Six patients received radical or partial nephrectomies, and all had a good prognosis. Three patients with metastatic kidney cancers died of the primary disease. Eleven patients (85.5%) were diagnosed pathologically by biopsies, allowing us to decide the course of treatment. However, because our tests also revealed one sampling error and one unspecified cancer, we determined that there are limitations to a renal biopsy.