Diagnostic tests in urology: percutaneous biopsy of renal masses

What's known on the subject? and What does the study add? Small renal masses are often detected incidentally with abdominal CT. About 80% of these masses are malignant. Many studies have investigated the diagnostic accuracy of small renal mass biopsy using various techniques. This has resulted in a broad range of published sensitivities and specificities without a clear guide for clinical use. This evidence-based medicine article addresses the clinical utility of renal mass biopsy. Based on a common patient scenario, a guide to calculating the probability of malignancy after a benign biopsy is provided. The scenario is used to show the potential influence of renal mass biopsy on clinical decision-making. This appraisal also discusses the limitations of the current literature, highlighting the need for multi-institutional studies with standardised biopsy techniques and a reliable comparator to confirm the clinical utility of this diagnostic test.