Also known as Cacchi-Ricci isease, Medullary sponge kidney is a congenital disorder of the kidneys characterized by a cystic dilatation of the collecting tubules in one or both kidneys. It has been estimated to occur with a prevalence of between 1 in every 5,000-10,000 individuals in a population1. In most cases, medullary sponge kidney affects only one kidney, in which case kidney function is usually preserved and individuals may be asymptomatic. However, these individuals are at increased risk for nephrolithiasis (kidney stones) and urinary tract infection.