Fig. 4

a Various depths of necrosis of the intestinal wall. Ischemic change with mucosal atrophy and submucosal edema is indicated by arrows. Regional transmural necrosis with lack of the mucosa and thinning of the intestinal wall is indicated by triangles. b Close-up image of the square in a. Ghost-like disappearance of the mucosal glands was identified in the borderline region. c Close-up image of the necrosis of all layers of the intestinal wall. Massive enucleation of smooth muscle cells was observed. No thrombus was identified (nor confirmed in a)