Pediatric vascular lesions.

The seminal work of Mulliken and Glowacki in 1982 elucidated the histological differences between hemangiomas and vascular malformations: the former are characterized by endothelial cell proliferation, whereas the latter contain mature endothelial cells. Hemangiomas proliferate and then involute, whereas malformations remain stable in size, growing proportionally with the child. Vascular malformations are classified by the predominant vessel type within the lesion (capillary, venous, arterial, and lymphatic). Histological classification therefore correlates with clinical behavior. Treatment of hemangiomas is generally conservative; however, intervention may be required as a result of cosmetically concerning, function-threatening (e.g., interference with eyesight), or life-threatening (e.g., airway obstruction) lesions. Options include steroid therapy, laser treatment, and/or surgical excision. Vascular malformations do not involute and are more likely to require treatment. Treatment options include embolization and surgical resection. Understanding the clinical course of pediatric vascular lesions allows the surgeon to find an appropriate balance between watchful observation, providing reassurance when appropriate, and intervention when needed.