Unilateral renal cystic disease

Unilateral renal cystic disease (URCD) is an uncommon, nonfamilial, and nonprogressive disorder of the kidney characterized by replacement of all or part of one kidney by multiple cysts. Initially thought to be a form of autosomal dominant polycystic kidney disease (ADPKD), its benign clinical course, lack of family history of cystic renal disease, and absence of cysts in other organs distinguish URCD from ADPKD. Review of English language published reports revealed only 6 documented cases of URCD in adults. We describe 3 cases (2 new) of adult URCD and review the diagnosis and management of this rare entity.