Shrinking and disappearing renal cysts

This paper presents 4 patients with what were thought to be hemorrhagic renal cysts that disappeared on follow-up, and an additional patient with a large superficial simple cyst that became smaller on follow-up examination. In 1 patient only was this appearance associated with renal scarring. One patient had uremic-acquired cystic disease of the kidney. The reasons for the disappearance or shrinkage are unclear, but might include bleeding into the cyst or rupture of the cyst into the perirenal space or the collecting system.