Medullary Sponge Kidney

**Definition:** A non-hereditary KIDNEY disorder characterized by the abnormally dilated (ECTASIA) medullary and inner papillary portions of the collecting ducts. These collecting ducts usually contain CYSTS or DIVERTICULA filled with jelly-like material or small calculi (KIDNEY STONES) leading to infections or obstruction. It should be distinguished from congenital or hereditary POLYCYSTIC KIDNEY DISEASES.

**Tree numbers:** - C12.050.351.968.419.403.500 - C12.200.777.419.403.500 - C12.950.419.403.500

**Synonyms:** - Kidney, Sponge - Cacchi Ricci Disease - Cacchi-Ricci Syndrome - Precalyceal Canalicular Ectasia