title: Diffuse microscopic angiodysplasia--a previously unreported variant of angiodysplasia. Report of a case.
abstract: OBJECTIVE
  The entity of diffuse microscopic angiodysplasia is described, and a patient with severe gastrointestinal hemorrhage because of this submucosal source of bleeding is reported.
  
  
  METHODS
  Case records of a patient with severe gastrointestinal hemorrhage were reviewed, and histologic findings were compared with colonoscopic and operative findings. The patient received 51 units of packed red blood cells over 3.5 months and remained undiagnosed, despite an exhaustive evaluation, until autopsy.
  
  
  RESULTS
  Ectatic veins, venules, and capillaries were present within the submucosa in virtually every section of the small and large intestine examined (79 of 86 sections). Histologic evidence of bleeding from these submucosal vessels was identified in three sites (colon, jejunum, and ileum). The absence of endoscopically visible lesions was explained by findings that vessels did not traverse the muscularis mucosa and that mucosal depth was normal. This case of diffuse microscopic angiodysplasia, therefore, represents a unique variant, because the vascular findings were so diffuse and the mucosa remained histologically and endoscopically uninvolved, despite severe bleeding.
  
  
  CONCLUSIONS
  Gastrointestinal bleeding from angiodysplasia is generally assumed to arise from endoscopically recognizable vascular ectasia within the mucosa. Thus, this case helps provide an explanation for some cases in which occult or massive bleeding is assumed to be secondary to angiodysplasia, even when endoscopic verification is not possible. Recognition of this disease process may require segmental resection or deep biopsy of endoscopically normal intestine.
authors.affiliation: Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA.
authors.forename: L B
authors.initials: LB
authors.lastname: Weinstock
authors.forename: R S
authors.initials: RS
authors.lastname: Larson
authors.forename: D J
authors.initials: DJ
authors.lastname: Stahl
authors.forename: J W
authors.initials: JW
authors.lastname: Fleshman
mesh_terms: D000368:Aged; D016888:Angiodysplasia / Q000145:classification / Q000209:etiology / Q000473:pathology*; D003108:Colonic Diseases / Q000150:complications; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000209:etiology / Q000473:pathology*; D006801:Humans; D007077:Ileal Diseases / Q000150:complications; D007413:Intestinal Mucosa / Q000098:blood supply / Q000473:pathology*; D007579:Jejunal Diseases / Q000150:complications