Incidence of Benign Renal Masses in a Contemporary Cohort of Patients Receiving Partial Nephrectomy for Presumed Renal Cell Carcinoma

The authors reviewed data on patients at a single institution, ultimately analyzing 1229 patients who underwent extirpative surgery for presumed RCC. They found that 236 (19.2%) patients had benign disease on final pathol-ogy. Despite advances in diagnostic technologies, the rate of benign pathology after presumed oncologic renal surgery remains high. Introduction: Over the past decade and a half, advances in diagnostic imaging as well as an increased utilization of active surveillance (AS) and renal mass biopsy (RMB) have led to an improved ability to identify benign lesions prior to partial nephrectomy (PN). We seek to examine the incidence of benign pathology at the time of PN in a contemporary cohort of patients undergoing PN for presumed renal cell carcinoma (RCC). Patients and Methods: We performed a chart review on a prospectively maintained database on a series of patients who underwent PN between January 1, 2006 and December 31, 2021 for solid renal masses concerning for RCC. Results: One thousand two hundred twenty-nine patients were included in the analysis, with 240 patients (19.2%) identified to have benign disease on final pathology. Of patients with benign disease, (23%) of patients had angiomyolipoma (AML) and 64% had oncocytoma. Between 2006 and 2021, there was a significant increase in the incidence of benign pathology after PN. When examin-ing 3-year rolling averages over this same time period, the incidence of oncocytoma appeared to increase while the incidence of AML decreased. Conclusion: Despite improvements in diagnostic tools and increased utilization of active surveillance, the overall incidence of benign pathology, particularly oncocytoma, did not decrease over time in this contemporary cohort of patients undergoing PN.