Safety and efficacy of biopsy of renal masses guided by ultrasound

Aim: Biopsy of renal masses has been controversially discussed since (1) a high percentage of lesions are thought to be malignant (2) the method is dangerous and (3) reveals a high rate of unconclusive findings. Recently a larger number of small renal tumors are reported at time of diagnosis with a relative high rate of benign lesions. Here we report on ultrasound-guided (us) renal biopsy of renal lesions to avoid operation.

Patients and methods: 21 patients with suspected renal masses for us-guided tumor biopsy and 50 consecutive patients with diffuse renal disease for us-guided renal biopsy to compare complication rate and therapeutic consequences (Trucut biopsy needle, 18G; Hitachi 8500 or HV 900 and Siemens Acuson Sequoia platforms].

Results: Benign lesions (42%, median size 30mm), malignant lesions (58%, median size 40mm). US guided biopsy influenced the therapeutic strategy in 50% of patients. There were 2/21 (10%) complications in US-guided biopsy of suspect renal masses (intratumoural bleeding, n=2) and 4/50 (8%) complications in US-guided kidney biopsies due to diffuse renal disease. The complication rate was not significantly different.

Conclusion: Biopsy of renal masses can be safely performed under us-guidance and reveals no significant difference in complication rates compared to kidney biopsy in diffuse renal disease. Renal tumor biopsy can avoid unnecessary surgery and reveals valuable information concerning the character and origin of renal masses.