Fig. 4
a Low magnification showing an intestinal ulcer (hematoxylin and eosin, × 20). b Changes in the blood vessels (thin black arrows) highlighted at the base of an ulcer (thick black arrow) (hematoxylin and eosin, × 40). c The arteries showing typical changes with luminal occlusion, myxoid subintimal matrix, and hypertortuous eosinophilic internal elastic lamina (hematoxylin and eosin, × 200). d One of the veins showing occlusive fibrin-rich thrombus (hematoxylin and eosin, × 100)