Fig. 3

Histology of the resected recto-sigmoid colon: a) Scanning power view of the ulcerated mucosa with adjacent normal colonic epithelium. b and c Scanning power views of the extensively necrotic mesentery. Viable (b) and ulcerated (c) colonic mucosa are seen respectively (arrows). d Medium power view of colonic epithelium showing acute ischemia characterized by epithelial loss with fibrosis and multiple micro-thromboemboli within the lamina propria. e Medium power view of necrotic mesentery with numerous foamy macrophages. Fibrosis is absent. A medium-size vessel shows nearly complete fibrous obliteration of the lumens. f, g, h, i, j High power views of medium size mesenteric arteries with fibrous intimal proliferation leading to near-complete luminal occlusion: hemotoxylin-phloxin-saffrin (f, g) and Verhoff Von Geason (h, i, j), the latter highlighting arterial internal elastic lamina