Fused Left Supernumerary Kidney with Single Blood Supply and Ureter

Abstract

Supernumerary kidneys, also known as accessory kidneys, refer to the presence of more than two kidneys. It is a rare congenital abnormality of the urinary system with only a few cases reported so far in literature. The extra kidney commonly has its own collecting system, blood supply, and well-defined encapsulated tissue. It may or may not be fused to the other kidneys by fibrous tissue or a parenchymal bridge. Imaging for vague abdominal symptoms may result in an incidental finding of the rare anatomical variant which may indicate an adjustment of routine physical activities to avoid renal trauma, as well as relevant considerations for surgical planning. We present a 62-year-old woman who presented with vague abdominal pains. Findings on physical examination were unremarkable. Her abdominal ultrasound scan showed two kidneys of about the same size fused together. Computed tomography urography showed two fused renal tissues of nearly same size on the left. The accessory kidney is more medial, slightly cranial. The native kidney is more lateral and more caudal. The native and accessory kidneys had only one blood supply, venous drainage, and a single ureter. As at the time of reporting, the patient has not received any intervention because there was no remarkable symptom noted. This case is rare and unique, in that it is a fused supernumerary kidney seen at the age of 62 and has a single blood supply and ureter. Imaging for vague symptoms can result in an incidental finding of a rare anatomical variant. It is also very essential for planning surgical intervention if need be.