Abnormal layering of muscularis propria as a cause of chronic intestinal pseudo-obstruction: A case report and literature review

Figure 1 Plain abdominal radiographs showed diffused dilatation of small bowel loops. A: Supine; B: Upright; C: Small bowel follow-through showed dilatation with thickening fold of almost the entire small bowel, from duodenum to ileum.

Figure 2 Exploratory laparotomy revealed thickening of the short small bowel. The bowel was pale, thickened, and an inflamed Tenia coli-like line was noted on the antimesenteric side from the duodenojejunal junction to 15 cm above the ileocecal valve.

Figure 3 Full-thickness biopsy from distal ileum. A: (HE, 20×) Hypertrophic muscularis propria with abnormal layering into 3 layers (IC: Inner circular; OB: Additional oblique; OL: Outer longitudinal); B: Delicate interstitial fibrosis and serosal muscularization (SE) are highlighted by Masson’s trichrome staining (20×).

Figure 4 Serosal aberrant muscularization into three bizarre layers of smooth muscle (Masson’s trichrome, 100×).

Figure 5 Immunohistochemical study. A: Smooth muscle α-actin; B: Desmin were strongly expressed in all layers of smooth muscle; C: CD117 showed interstitial cells of Cajal network; D: S100 highlighted Auerbach’s neural plexuses; (20×).