Multiple unilateral renal cysts in two children.

We report two children who presented with multiple renal cysts involving only one kidney and in whom there was no family history of renal disease and who did not have syndromes known to be associated with renal cystic disease. This unilateral involvement may represent a distinct entity, which has only been previously described in three cases; however, long-term follow-up will be needed to confirm this hypothesis. We illustrate the sonographic and computed tomographic findings, and the differential diagnosis is discussed.