- Vascular anomalies are vascular lesions noted at birth or that arise during the first months of life. The purpose of this article is to illustrate how vascular anomalies involve the extremities of infants and children. Cases illustrate the range of vascular anomalies as defined by the International Society for the Study of Vascular Anomalies. Both clinical and imaging features of extremity vascular anomalies are discussed. A comprehensive classification that uses a simple, universal, and common terminology is presented. Ultrasound and magnetic resonance imaging are noninvasive diagnostic tools that are widely used in pediatric practice, in particular to categorize many of these lesions, provide a diagnosis if there is clinical doubt, evaluate these lesions fully, and guide management and therapy.