This is a report of 2 widely differing clinical cases with similar pathological changes, viz., hyaline capillary and arteriolar thrombosis. Case 1 had thrombo-cytopenic purpura. and acquired hemolytic icterus. Postmortem examination revealed hyaline thromboses of arteri-oles and capillaries in various organs but most profuse in the myocardium. The heart, however, showed no endocarditis and patient died without azotemia. Case 2 had the skin lesions of acute lupus erythematosus following exposure to the sun. She had an evident mitral endocarditis, pericarditis, pneumoritis and renal involvement. She exhibited numerous petechial phenomena. She developed anuria, an increasing azotemia and died in uremia. The diagnosis of atypical verrucous endocarditis was made with accompanying acute lupus erythematosus. This was borne out at the postmortem examination. Microscopically the essential lesion was the same arteriolar and capillary thrombosis. Inasmuch as both these cases had the same underlying pathological lesion[long dash]hyaline capillary and arteriolar thrombosis[long dash]they were considered to represent the same disease which was, perhaps, a variant of periarteritis nodosa. The subject of acute lupus erythematosus with visceral lesions and the possible theoretical causation of the hyaline thrombi were discussed. Ricker''s hypothesis of the formation of conglutinative thrombi as the result of toxic causes was thought the most plausible. Schwartzman''s phenomenon of tissue reactivity was also discussed in its possible relationship to this disease.