Annular ulcer of the stagnant ileum. A clinicopathological study on the morphogenesis

Four cases of chronic annular ulcers of the stagnant ileum were described. The ulcers developed at the necks of the distended oral blind loops formed by side-to-side intestinal anastomoses in 3 cases and orally to the site of ileal stenosis by a congenital mesodiverticular band in one case. All ulcers were shallow and characterized by desmoplastic reaction and extensive veno-occlusive lesions. Arterio-occlusive lesions were sparse except for the youngest case. Intestinal ischemia caused by transient or recurrent ileal intussusception is the possible cause of these ulcers.