Fine-needle percutaneous biopsy of renal masses with helical CT guidance

PURPOSE: To evaluate the feasibility, accuracy, and clinical role of fine-n eedle percutaneous biopsy of renal masses, with helical computed tomographi c (CT) guidance. MATERIALS AND METHODS: In 63 patients (mean age, 62 years), 73 biopsies wer e performed. The median tumor size was 4.0 cm. Tumor biopsy was performed w ith and 18-guage needle by using helical CT guidance in an outpatient setti ng. Two to four cores per tumor were obtained. RESULTS: Biopsy material was insufficient for analysis in 15 (21%) procedur es. The median tumor size of failed or successful biopsies was 3.0 or 4.8 c m, respectively (P=0.3) A benign lesion was found at eight biopsies. Two sa mples were suspicious for renal cell carcinoma (RCC). RCC was found in 38 b iopsy samples. The remainder were transitional cell carcinoma, metastasis, lymphoma, or sarcoma. Twenty-six patients underwent nephrectomy. The accura cies of biopsy for histopathologic and Fuhrman nuclear grade evaluation wer e 89% and 78% respectively. For tumors of 3.0 cm or smaller or larger than 3.0 cm, 37% (11 of 30) or 9% (four of 43) had failure of biopsy, respective ly (P=.006). No substantial morbidity occurred. CONCLUSION: Fine-needle biopsy with helical CT guidance is accurate for the histopathologic evaluation of renal masses without morbidity. Indications are renal lesions that do not have the typical radiologic features of RCC, Bosniak category III or IV cystic lesions, and locally advanced or metastat ic RCC.