Open transperitoneal partial nephrectomy in a horseshoe kidney

We report the case of a 50-year-old Tibetan man who presented to an outpatient urology clinic after abdominal ultrasound for poorly defined abdominal pain demonstrated horseshoe kidney (HK) with a right moiety ~3.7 cm mass further characterised using contrast-enhanced CT scan (CECT). This dedicated imaging confirmed HK with a heterogeneously enhancing right upper pole 3.1 cm×3.7 cm×2.7 cm mass. Due to suspicion for aberrant vasculature on CECT, renovascular angiography was performed, which revealed recruitment of a right paravertebral vessel alongside two right renal moiety arteries and multiple right renal moiety veins. Based on vascular complexity and the surgical exposure required for arterial clamping, open transperitoneal right partial nephrectomy was preferred to minimally invasive techniques. Postoperative course was complicated by ileus, which resolved with standard management. Pathologic analysis revealed complete resection of a 5.0 cm Fuhrman grade II clear cell renal cell carcinoma.