Current theories on the pathogenesis of infantile hemangioma.

Infantile hemangiomas are the most common tumors of infancy and although the natural history and progression of these lesions are well described, their origin remains unclear. Considerable progress has been achieved in the past two decades towards understanding the etiology of these lesions. New investigations have produced sophisticated hypotheses on the origin of these tumors and their behavior. These include suggestions of placental origin, intrinsic defect or somatic endothelial mutation, and extrinsic factors creating a conducive milieu for growth. While no current hypothesis explains all the characteristics of infantile hemangiomas, continued research targeting pathophysiology will ultimately lead to new treatment options.