Vascular tumors in children.

Tumors with a vascular component are the most common masses seen in children. Malformations and hemangiomas predominate. Hemangiomas have a biphasic natural history consisting of initial proliferation followed by spontaneous involution; these tumors rarely require surgical intervention. Malformations present at birth or shortly after birth and have a wide spectrum of clinical presentations depending upon their predominant cell type and rheology. Physical examination and MR imaging will effectively define most of these anomalies. Surgery is reserved for very symptomatic lesions and is effective in all but the fast-flow, Type C group of malformations. Glomus tumors, pyogenic granulomas and both traumatic and iatrogenic aneurysms are also seen in the pediatric age group. All are benign and effectively treated surgically. Malignant vascular tumors are rare in this age group.