Pediatric cystic diseases of the kidney.

Pediatric renal cystic diseases include a variety of hereditary or non-hereditary conditions. Numerous classifications exist and new data are continuously published. Ultrasound is the primary technique for evaluating kidneys in children: conventional and high-resolution US allows a detailed visualization of renal parenchyma and of number, size and location of the cysts, hence representing the most important diagnostic imaging technique for the first diagnosis and follow-up of these young patients. The purpose of this pictorial essay is to review the spectrum of renal cystic lesions in children from simple, complex or malignant single cysts to the several poly/multicystic kidney diseases.