Supernumerary left kidney

A 77-year-old woman with a history of right breast cancer and recently diagnosed B-cell lymphoma was evaluated for developing renal insufficiency with ultrasound and a Tc-99m MAGS renal scan. These studies demonstrated the presence of 3 functioning native kidneys. Supernumerary kidneys are a very rare congenital anomaly, and the use of renal scintigraphy plays an important role in both the diagnosis and the evaluation of renal function in such patients.