Medullary Sponge Kidney

Medullary sponge kidney (MSK) is a birth defect of the tubules - tiny tubes inside the kidneys. In MSK, tiny sacs called cysts form in the inner part of the kidney (the medulla), creating a sponge-like appearance. The cysts keep urine from flowing freely through the tubules. MSK is present at birth but symptoms typically do not occur until adolescence or adulthood. Many people with MSK have no symptoms, but others may have blood in the urine, kidney stones, and urinary tract infections. Rarely, MSK leads to more serious problems, such as chronic pain and kidney failure. The cause for MSK is unknown but some cases may run in families. Treatment is aimed at preventing and removing kidney stones and treating urinary tract infections with antibiotics.