Ultrasound-Guided Core Needle Biopsy for Renal Sinus Masses: A Valuable Tool in the Preoperative Evaluation of Urologic Tumors

Background The renal sinus's complex anatomy challenges imaging diagnosis. Ultrasound-guided biopsy shows promise for renal sinus masses due to its real-time, radiation-free, and cost-effective advantages, but its efficacy and safety need validation. Objective To evaluate the diagnostic performance, safety, and clinical impact of ultrasound-guided percutaneous core needle biopsy for renal sinus masses. Materials and Methods A retrospective analysis was conducted on 51 patients who underwent ultrasound-guided renal sinus biopsy at a tertiary medical center between April 2010 and October 2020. Inclusion criteria were renal sinus masses with indeterminate imaging features. Diagnostic yield, complications (graded by the Clavien–Dindo classification), and treatment plan modifications were recorded. Univariate logistic regression analysis was used to identify factors associated with complications. Results The overall diagnostic yield was 90.2% (46/51), with malignant lesions accounting for 88.2% (45/51), including urothelial carcinoma of the renal pelvis (43.1%, 22/51) and clear cell renal cell carcinoma (31.4%, 16/51). Benign lesions accounted for 11.8% (6/51). The complication rate was 7.8% (4/51), including perirenal hematoma and gross hematuria (Clavien–Dindo grade I–II), with no cases of needle tract seeding or severe complications. Biopsy results altered treatment plans in 23.5% (12/51) of patients, and unnecessary surgery was avoided in 7.8% (4/51). Tumor size, location, number of needle passes, and tract ablation were not significantly associated with complications (all p > 0.05). Conclusion Ultrasound-guided percutaneous biopsy of renal sinus lesions demonstrates high diagnostic efficacy (90.2%) and safety (complication rate: 7.8%) in complex renal sinus diseases. It enables precise clinical decision-making and helps avoid overtreatment. Its advantages of real-time imaging and absence of radiation make it a valuable tool in the management of renal tumors.