THE DISEASE thrombotic thrombocytopenic purpura refers to a condition characterized by an unusual triad: hemolytic anemia, thrombocytopenic purpura, and multiple hyaline thrombi throughout the small vessels of the body. The occurrence of thrombi in cranial blood vessels gives rise to the characteristic cerebral symptoms. Since the name thrombotic thrombocytopenic purpura, first suggested by Singer and co-workers,11 fails to include any mention of the hemolytic anemia, a modification of this term to thrombohemolytic thrombocytopenic purpura is suggested.
Forty-six cases of thrombohemolytic thrombocytopenic purpura (hereafter referred to as T. T. P.) have been described in the literature up to the present time. As the disease becomes better known, the diagnosis can often be made before death and studies can be carried out on the disease mechanism. An opportunity has been afforded recently to study two cases correctly diagnosed before death. These cases and the associated studies are described below, together with