Thrombotic thrombocytopenic purpura. Report of a case presenting as a chronic neurological disorder and characterized by unusual histological findings.

A case of thrombotic thrombocytopenic purpura in a 50-year-old woman is described. Almost the whole course of the disease, lasting 18 months, was characterized by a bizarre neurological disorder, and the haematological manifestations first appeared at a late stage. In many organs a vast number of arterioles and capillaries contained plugs of a fibrinoid material, and fibrinoid was subendothelially accumulated in a few of these vessels; but, in addition, mediumsized arteries of the myocardium were also obstructed by this same material. There were also verrucal endocardiosis of the mitral valve and slight thickening of the glomerular basement membranes. The striking diffusion of a pathological substance through damaged cerebral vessel walls into the nervous tissue seems to be a significant contribution to the understanding of the pathogenesis of the vascular pathology of thrombotic thrombocytopenic purpura.