Renal medullary cystic disease. Findings at urography and ultrasonography.

Medullary cystic disease (MCD) is an uncommon renal disease with adult onset and autosomal inheritance, eventually progressing to terminal renal failure. It may be difficult to identify because of insufficient diagnostic tools. At urography, the same ring-shaped accumulation of contrast medium at the corticomedullary junction was observed in two patients (mother and son) suffering from MCD. To our knowledge this observation has not been reported before.