Update on vascular tumors of infancy

Advances have been made in the pathogenesis, diagnosis and management of vascular tumors of infancy in the past year. Propranolol therapy for infantile hemangiomas (IH) is now being used widely, and case reports, series, and adverse effects are reviewed. Kaposiform hemangioendothelioma and tufted angioma are less common than IH but more often associated with coagulopathy (Kasabach-Merritt phenomenon).

Recent work suggests that stem cells, mediated by the Notch signaling pathway, may become proliferating endothelial cells that comprise IH. Large, segmental IH are more likely to develop complications that can include life-threatening bleeds; however, solitary large IH do not appear to increase the risk of hepatic IH. Segmental IH may herald underlying structural anomalies of the brain, cerebral, and cardiac vessels (PHACE syndrome--Posterior fossa defects, Hemangiomas, Arterial anomalies, Cardiac defects and Coarctation of the aorta, Eye anomalies), and new criteria aid in diagnosis. Propranolol therapy is effective in life-threatening IH and appears to stop growth and hasten involution in proliferative and plateau phase IH. Adverse effects include bradycardia, hypotension, hypoglycemia, and bronchospasm. A recent review of kaposiform hemangioendothelioma finds that an associated coagulopathy (Kasabach-Merritt phenomenon) occurs in 72%.

Propranolol appears to be tremendously efficacious with fewer side effects than systemic corticosteroids, but its proper place in the therapeutic algorithm for IH and other vascular tumors awaits controlled study.