Clinical implication of selective renal tumor biopsy

Since 1982, we have performed selective needle core biopsy under ultrasonic real time guidance for the specially indicated cases with a suspected renal tumor. Between June 1982 and April 1994, 100 renal tumor cases were examined by biopsy with a success rate of 97%. We evaluated 63 cases of renal cell carcinoma, 7 cases of transitional cell carcinoma, 2 cases of metastatic carcinoma, and 25 cases of benign lesions such as angiomyolipoma and hemorrhagic cyst. In 3 cases no tissue was obtained. No complications occurred except for dissemination in only one case of angiomyoliposarcoma. Recently incidental renal tumors tend to increase more and more, and small incidental renal tumors may have a high possibility of benign tumor compared with symptomatic renal tumor. Selective renal tumor biopsy may be valuable in the diagnosis of an incidental renal tumor which is difficult to differentiate between malignant tumor and benign tumor by several imaging methods. From our experiments and other reports, the clinical implication of renal tumor biopsy is discussed.