Idiopathic multiple hemorrhagic sarcoma was described by Kaposi in 1872 under the title “idiopathic multiple pigment sarcoma.” At that time a number of conditions, since regarded as entities, were confused both clinically and histologically—affections such as some of the lymphoblastomas or lymphogranulomas and some of the sarcomas. Previous to 1872, the Kaposi type of sarcoma had been observed and described under several names. Kaposi placed most of the conditions under the general heading of sarcoid tumors. He described A, B, and C sarcomatoses, the B type representing what has since been known as Kaposi's sarcoma. In recent years the term sarcoid has been limited— with the exception of the Spiegler-Fendt sarcoid, which is probably a lymphoblastoma (Zeisler; Lewis and Satenstein)—to two affections which are thought to belong to the tuberculosis group of skin diseases. Some of the original sarcoid tumors are now known to be sarcomas, while others are recognized as lymphoblastomas. Even Kaposi's sarcoma B—idiopathic multiple hemorrhagic sarcoma—is now thought by some investigators to be more or less closely related to the lymphogranulomas. Since Kaposi's original contributions, a voluminous literature has developed. Kren, for instance, has written a monograph of 113 pages which contains ten pages of closely crowded references. Many of the articles are argumentative. While all authors agree that the disease is a clinical and histological entity (not an etiologic entity), there is considerable controversy relative to nosology, pathogenesis, cytology, and histological minutiae. A glance at the bibliography of the affection indicates this difference of opinion, since many authors have expressed their convictions in the names they have given the disease, as shown in Table I. Regardless of the controversy over nomenclature and classification, however, the affection is generally known as Kaposi's sarcoma, or multiple idiopathic hemorrhagic sarcoma, as suggested by Köbner in 1891.