CT-guided percutaneous fine needle biopsy of solid kidney tumours.

Objective: This study was designed to evaluate the reliability and the role of percutaneous needle biopsy in the diagnosis of renal masses. Materials and Methods: 85 biopsies were performed in 74 patients (mean age: 62+/-14 years). The median tumour diameter was 4.44+/-2.53 cm. Biopsies we re performed with an 18G ASAP* needle with CT guidance. 2 to 4 cores were o btained per patients. All biopsies were performed as an outpatient procedur e. Results: Biopsies were uninterpretable in 15 cases (17%) (13 with normal or no renal tissue and 2 necrotic samples). A benign lesion was detected in 8 cases (4 fibrous lesions, 4 infectious le sions). In 3 cases, biopsies were suspicious of cancer, which was confirmed on definitive histology. In 59 cases, biopsies were neoplastic: 6 benign t umours (4 oncocytomas, 1 angiomyolipoma, 1 cystadenoma), 42 renal cell carc inomas (RCC) (conventional: 32, chromophobe: 3, tubulopapillary: 7), 5 urot helial carcinomas, 3 metastases, 2 lymphomas and 1 sarcoma. The median Furh man grade was 2. 30 RCC were operated. The correlation coefficient for the biopsy and pathol ogy histological type was 0.90. The median pathological Furhman grade was 2 . There was no morbidity, post-biopsy medical management was never required . Conclusion: Biopsy of renal masses is reliable for evaluation of the histol ogical type. The introduction of the CT scope should increase the accuracy of biopsies. The morbidity is low compared to that of diagnostic surgery.