Multiple idiopathic hemorrhagic sarcoma of Kaposi has been regarded by various authors since the original description in 1872 as of either neoplastic, infective, vascular, or reticuloendothelial origin. Diverse though the etiological possibilities may appear, all investigators agree that it is a disease of vessels, particularly the blood vessels, though the lymphatic channels have also been implicated. The condition is rare, but the literature is copious, the attention which the disease has attracted being reflected in the 28 synonyms tabulated by Choissier and Ramsey (1939) in their paper on the subject. Kaposi himself, in his "Pathologie und Therapie der Hautkrankheiten" (1880) describes the disease as a type of cutaneous sarcoma affecting the blood vessels and having an unfavorable prognosis. Koebner (1891), in reviewing a case, first suggested the term "multiple idiopathic hemorrhagic sarcoma," which is that now usually employed. Semenow (1897) suggested that the disorder