Case report: Atypical polycystic kidney disease.

Atypical or unilateral polycystic kidney disease is a rare entity that is found incidentally and is characterized on imaging as asymmetric or unilateral distribution of cysts confined to the kidneys. We present a case of an incidental finding of atypical polycystic kidney disease in a 72-year-old male. Computed tomography imaging showed asymmetric distribution of cysts only in the kidneys and the patient had no genitourinary symptoms, had normal renal function, and did not have a family history of renal disease. Although considered to be benign, rare cases of progression of atypical polycystic kidney disease to bilateral polycystic kidney disease has been documented in the literature, which portends a worse prognosis. It is important for clinicians to be aware of this entity so that patients can be monitored periodically for progression of disease.