medullary sponge kidney
Medullary sponge kidney is a benign condition characterised by multiple, smooth wall cysts that are confined to the renal papillae. From 1 in 5000 to 1 in 20,000 people are affected, males more commonly than females. Most patients are diagnosed in their 5th or 6th decade.
MSK is thought to arise as a result of anomalous development of the collecting ducts. It may affect one or both kidneys.
As many as 50% of patients develop renal calculi, usually calcium oxalate and calcium phosphate, which present as areas of calcification in the renal papillae on abdominal x-ray. Many patients are asymptomatic but others repeatedly form and pass stones, resulting in painful colic.
Although not possible to completely rid most patients of all their stones, the use of lithotripsy has been shown to reduce the frequency of painful stone passage.
Last reviewed 01/2018