Abstract: | Two patients with malignant histiocytosis were found to have capillary occlusion by aggregates of neoplastic histiocytes, in skeletal muscle in one, and in renal glomeruli in the other. One patient had clinical evidence of similar occlusions in the arterioles and capillaries of the ocular fundi. Occlusion of small vessels by tumour cells may explain the confusion of both patients. |