Laterally shifted urinary bladder mimicking a supernumerary kidney.

Tc-99m dimercaptosuccinic acid (Tc-99m DMSA) is often used to evaluate renal cortical anatomy and differential renal function. The authors describe a DMSA scan that showed extrarenal uptake that strongly suggested a supernumerary kidney. However, a subsequent Tc-99m MAG3 renogram revealed a laterally deviated bladder, a novel differential for an apparent pelvic kidney concentratina DMSA.