Utility of renal mass biopsy in a UK tertiary referral centre

ObjectiveTo determine the value of percutaneous biopsy in a UK cohort of patients with renal mass lesions, with particular reference to its utility for the prediction of histological cell-type, Fuhrman nuclear grade and necrosis.Patients and methodsFrom May 1999 to September 2009, 71 patients underwent renal mass biopsy (RMB), most for indeterminate renal masses or in those with a mass lesion and extrarenal malignancy. Approximately one-third were for small renal masses (≤4 cm). Biopsy results were correlated with final surgical specimen pathology or with the outcome of surveillance in those not receiving surgery.ResultsOf 71 biopsies, there were 65 (91.5%) considered diagnostic biopsies, of which 59 (90.8%) were malignant and 6 (9.2%) were benign. 30 patients with biopsy-proven malignancy underwent extirpative surgery, with a diagnostic accuracy for biopsy of 100%. Accuracy of RMB for histological sub-type, Fuhrman nuclear grade and tumour necrosis was 80.0%, 52.3% and 80.0%, respectively. Bleeding complications were seen in 2 (2.8%) patients, and there were no cases of needle track seeding.ConclusionRMB is a safe and accurate method for determining underlying malignancy, with an acceptable non-diagnostic rate. Although concordance for histological tumour sub-type and necrosis was reasonable, values for nuclear grade were less reliable.