Kaposiform hemangioendothelioma. An aggressive, locally invasive vascular tumor that can mimic hemangioma of infancy.

BACKGROUND: Kaposiform hemangioendothelioma is a rare, aggressive vascular proliferation in children that is clinically and histologically distinct from hemangioma of infancy. It often manifests later than infantile hemangioma, and complication by Kasabach-Merritt syndrome is common.

OBSERVATIONS: We examined 3 children with kaposiform hemangioendothelioma, all of whom were initially misdiagnosed as having infantile hemangioma. All 3 children developed Kasabach-Merritt syndrome, in association with a rapidly growing cutaneous vascular mass. Treatment with systemic corticosteroids, interferon alfa, vincristine, and radiation therapy appeared to halt progression of the disease. None had evidence of human herpesvirus 8 infection.

CONCLUSIONS: Cutaneous kaposiform hemangioendothelioma may appear in early infancy but often appears months to years later. It is frequently complicated by Kasabach-Merritt syndrome, has no known association with Kaposi sarcoma related to human immunodeficiency virus infection, and demonstrates aggressive local behavior with invasion but not distant metastasis. Awareness of this entity is important to prevent a mistaken diagnosis of common hemangioma of infancy.