Malignant hemangioendothelioma, localised to the skeleton of the lower limbs, to the exclusion of any other bony or visceral involvement, complicated by hemolytic anemia and spontaneous fractures, edl to death in spite of bilateral amputation, less than one year after its chance discovery. The multifocal character of the bony lesions, which is common, may suggest either rapidly developing metastases, or multicentric development of the tumour. The clinical, radiological and laboratory signs--pure osteolysis of large size without condensation nor periostosis, are not specific. Pathological examination permits recognition of the vascular origin of the tumour but does not always permit one to recognize its malignant nature. Treatment, which is mainly surgical, is often ineffective.