Malignant endovascular papillary angioendothelioma is a rare vascular tumor of childhood that was first defined by Dabska in 1969. Microscopically, this tumor is composed of anastomosing vascular channels, some of which contain papillary projections or tuft-like structures sometimes resembling renal glomeruli. Although cases have been reported with metastases to regional lymph nodes, the long term prognosis for patients with these tumors is generally good. We have studied this tumor by light and electron microscopy as well as immunohistochemical techniques in a 10-year-old boy. A review of the literature on this rare entity is presented.