Orbital vascular anomalies

Abstract

Vascular anomalies are classified into vascular tumors and vascular malformations based on the classification system of the International Society for the Study of Vascular Anomalies (ISSVA) [1, 2]. Vascular tumors are characterized by proliferation and tumor enlargement, and the most common vascular tumor is infantile hemangioma, while a less common vascular tumor is hemangiopericytoma. Vascular malformations consist of non-proliferating vascular lesions in which blood flow is misdirected through anomalous channels. Malformations exist on a spectrum, ranging from high-flow arteriovenous malformation (AVM), low-flow venous (varix) and lymphovenous malformations, and capillary-venous malformations. Flow characteristics influence the natural history of vascular anomalies and are helpful in making the correct diagnosis.