Understanding vascular anomalies: a common language for doctors

Vascular anomalies are benign vascular lesions of childhood and complex lesions should be managed within a specialized multidisciplinary team. They have been poorly understood owing to a lack of a common nomenclature among the various medical specialities as the subject remains neglected in undergraduate and postgraduate courses. The seminal work of Mulliken and Glowacki in 1982 established the foundations of the understanding of vascular anomalies by classifying them according to their histopathological and clinical features. Based on these findings, in 1996 the International Society for the Study of Vascular Anomalies classified vascular anomalies into vascular tumours (haemangiomas and others) and vascular malformations (capillary, lymphatic, venous, arteriovenous or a combination). Their characteristics and management differ greatly. Haemangiomas are the most frequent tumours of infancy. They are benign, transitory and self-limiting vascular lesions that exhibit cellular proliferation. Usually not present at birth, haemangiomas undergo transformation through a cycle of rapid proliferation over 6 months, to a variable period of involution and spontaneous regression over years. Their management is usually conservative, with active treatment reserved for the presence of functional or cosmetic complications (ulceration, obstruction and distortion of vital structures). Vascular malformations are structural anomalies of vascular morphogenesis without cellular proliferation. They present at birth, do not regress spontaneously and are subclassified as low-flow (capillary, lymphatic and venous) and high-flow (arteriovenous) lesions. Their effects may be those of a space-occupying lesion: infection, bleeding, pain or coagulopathy. Treatment options include dye laser (capillary), percutaneous sclerotherapy and surgery (venous and lymphatic) and embolization and surgery (arteriovenous).