Ultrasound-guided percutaneous core biopsy of renal sinus masses: diagnostic yield, safety, and clinical impact

Renal sinus lesions present diagnostic challenges due to their complex anatomy and heterogeneous pathology. Reliable tissue acquisition is essential for guiding treatment decisions, yet evidence on the performance of ultrasound (US)-guided biopsy in this setting remains limited. To evaluate the diagnostic yield, safety profile, and clinical impact of US-guided percutaneous core needle biopsy(CNB) for renal sinus masses at a tertiary care center. We conducted a retrospective analysis of 51 patients who underwent US-guided percutaneous CNB for indeterminate renal sinus masses between 2010 and 2020. Diagnostic yield, histopathological results, complication rates (graded by Clavien-Dindo classification), and subsequent changes in clinical management were assessed. Univariate logistic regression was employed to identify factors associated with complications. Biopsy achieved a diagnostic yield of 90.2% (46/51). Malignant lesions accounted for 88.2% of cases, most commonly upper-tract urothelial carcinoma (43.1%) and clear cell renal cell carcinoma (31.4%). Benign lesions comprised 11.8%. The overall complication rate was 7.8% (4/51), limited to grade I–II events (perirenal hematoma, hematuria); no major complications or needle tract seeding were observed. Biopsy findings altered treatment in 23.5% of patients, and unnecessary surgery was avoided in 7.8%. Tumor size, location, and number of needle passes were not significantly associated with complications (all P > 0.05). US-guided percutaneous CNB of renal sinus masses is a safe and effective diagnostic approach, providing high tissue yield with low morbidity. By enabling accurate diagnosis and reducing overtreatment, this technique represents a valuable tool in the management of complex renal tumors.