Malignant angioendotheliomatosis is an intravascular proliferation of tumour cells in the small arteries, veins and capillaries. Its lymphomatous origin has been proved recently by immunohistochemistry. It is a rare, generally rapidly fatal condition. Less than 150 cases have been reported in the literature. We report three cases. Long course fever with delayed neurologic disturbances were observed in the first case and long course fever, hyponatraemia, corticotropic and gonadotropic insufficiency in the second. The third case began with febrile meningo-encephalitis. Diagnosis was made at autopsy in the two first cases and on evidence from kidney needle-biopsy in the third. Clinical manifestations are polymorphic and frequently simulate vasculitis. Neurologic signs are the most common. Histologically, kidneys, skin, endocrine glands, lungs, muscles and most of the organs may be involved. Surprisingly lymph nodes, bone marrow and spleen are often free from disease. Current treatment is based on polychemotherapy. Earlier diagnosis of the disease should improve the prognosis as observed in our third patient.