Crohn disease: phases

• nonstenotic phase:
  • blunting, flattening, distortion, straightening, and thickening of mucosal folds (early event from obstructive lymphadema)
  • aphthous ulcers: nodules with shallow central ulcerations
  • "cobblestoning": serpiginous ulcers separated by areas of edema
  • pseudopolyps: hyperplastic mucosa between denuded mucosa
  • postinflammatory polyps
  • "skip lesions" (90%)
  • pseudodiverticula: bulging area of normal wall opposite affected scarred wall, mostly on the antimesenteric side
  • separation and displacement of small bowel loops (from increase in mesenteric fat, enlarged nodes, or perforation with abscess formation)

• stenotic phase:
  • "string sign": strictures (most in TI) in rigid loops
  • normal proximal loops may be dilated with stasis ulcers and fecoliths

see: Crohn disease

© 2002, C.E. Kahn, Jr.
2002-04-18