Rare case of triple kidney with horseshoe fusion

Congenital anomalies of the kidney and urinary tract represent a heterogeneous group of malformations, often detected incidentally but occasionally associated with complications. Among them, the coexistence of a supernumerary kidney and a horseshoe configuration is exceptionally rare. We report the case of a 63-year-old man presenting with persistent left lumbar pain. Imaging demonstrated 3 kidneys: 2 partially fused in the left renal fossa, with the lower 1 additionally fused to a midline horseshoe kidney. All kidneys showed preserved parenchyma and function, with a few nonobstructive calculi and independent vascularization. This case emphasizes the importance of imaging in detecting and characterizing rare renal fusion anomalies, providing useful insights into their embryological and clinical significance.