Epidemiology

The exact prevalence of medullary sponge kidney (MSK) in the general population is unknown. Most patients remain asymptomatic, and the condition can be an incidental finding on radiologic investigations for other reasons.[3] One study estimated the prevalence to be 5 per 100,000 population.[8] In patients examined with intravenous urography (IVU), the prevalence was estimated to be about 0.5% to 1%.[9] Other studies have estimated the prevalence to be about 3% to 5% in patients who are renal stone formers, although higher estimates (up to 20%) have been reported.[3][10]

Some studies have suggested MSK is more common in women, whereas others have found no difference between the sexes.[11] While it is a developmental disorder, it is often not diagnosed until the third decade of life.[2] The disease most often presents in the 30- to 50-year age group. Epidemiologic studies have not shown any evidence that the prevalence is higher in certain ethnic or racial groups.

The differences in estimated prevalences are thought to be due to differences in the interpretation of radiologic findings and the characteristics of the populations studied. Furthermore, noncontrast computed tomography scan has replaced IVU as the diagnostic standard for renal stones, and this will probably lead to a decrease in the detection rate of MSK in the future.[3][12] 

Use of this content is subject to our disclaimer