Approach to simple kidney cysts in children.

The finding of a simple kidney cyst in a child can pose a diagnostic and management challenge for pediatric nephrologists, urologists, and primary care providers. The reported prevalence varies from 0.22 to 1% in large ultrasonography-based series of more than 10,000 children each. The true prevalence, however, may be higher or lower, as factors such as variations in referral patterns, indications for ultrasonography, or technical considerations could impact prevalence rates. For many patients, simple kidney cysts may be found incidentally when imaging is performed for another indication. Although simple cysts can occur in children, they may also represent the first sign of autosomal dominant polycystic kidney disease (ADPKD) or other less common cystic kidney diseases. Definitive guidelines regarding the evaluation and monitoring of children with simple kidney cysts have not been established. The desire on the part of the practitioner and/or parents to establish a definitive diagnosis should be balanced with the cost and inconvenience of repeated imaging and visits with specialists. The goals of this review are to (1) outline the definition, epidemiology, clinical presentation, and natural history of simple kidney cysts in childhood; (2) describe clinical features that could suggest a diagnosis other than a simple kidney cyst; and (3) present a suggested framework for evaluating and monitoring of children with one or more simple kidney cysts.