Coexisting Renal Artery Stenosis and Large Angiomyolipoma in a Solitary Kidney: A Therapeutic Dilemma

Title: Coexisting Renal Artery Stenosis and Large Angiomyolipoma in a Solitary Kidney: A Therapeutic Dilemma Authors: Tilahun YB, Mentor/Attending: Sekar A Background: Angiomyolipomas (AMLs) are the most common benign renal tumors, typically presenting as incidental findings. However, large AMLs can lead to life-threatening complications such as retroperitoneal hemorrhage, particularly in the setting of a solitary kidney. The presence of concomitant renal artery stenosis (RAS) further complicates management, posing a unique therapeutic challenge in balancing the need to prevent hemorrhage, preserve renal function, and optimize renovascular perfusion. Case: A 77-year-old African American woman with a history of left nephrectomy for renal AML presented with an incidental finding of multiple right renal AMLs, including a dominant 10x7 cm mass. Hemodynamically significant ostial RAS was also discovered during pre-embolization angiography, with a translesional gradient of 15 mmHg. Multidisciplinary discussions were conducted among Nephrology, Urology, and Interventional Radiology to explore management options. Selective transcatheter embolization of the dominant AML was successfully performed, with a satisfactory decrease in size to 9.1x7.5x8.4 cm on follow-up imaging at 3 months. Vascular stenting was deferred as the patient's hypertension was well-controlled on medical therapy with amlodipine. Conclusion: The management of complex AMLs in solitary kidneys with concurrent RAS requires an individualized approach guided by multidisciplinary collaboration. Selective embolization offers a nephron-sparing strategy for large AMLs, aiming to mitigate the risk of hemorrhage while preserving renal function. However, the impact of revascularization on rupture risk in this setting remains unknown, and the indications for intervention in RAS affecting solitary kidneys are not well-defined. In this case, a conservative approach with selective embolization and medical management of hypertension was favored. Further research is needed to better elucidate long-term outcomes and guide therapeutic decision-making in this challenging clinical scenario. Close surveillance remains crucial to monitor treatment response and assess the need for further intervention.