title: Gastric duodenal metaplasia in duodenal adenomas.
abstract: BACKGROUND
  In cases of known aetiology, gastric duodenal metaplasia (GMD) is a reversible lesion. In cases of unknown aetiology, the fate of GMD remains elusive. GMD was recently found in a duodenal adenoma.
  
  
  OBJECTIVE
  To audit the frequency of GMD occurring in a cohort of duodenal adenomas.
  
  
  METHODS
  Filed H&E-stained sections from 306 consecutive duodenal adenomas were investigated for the presence of GMD.
  
  
  RESULTS
  68% of the adenomas (n = 208) were from patients with familial adenomatous polyposis (FAP), and the remaining 32% (n = 98) were sporadic. GMD was found in 31.7% (66/208) of the duodenal FAP adenomas and in 59.2% (58/98) of the duodenal sporadic adenomas (p<0.05). The causes for this difference are elusive.
  
  
  CONCLUSIONS
  As for other metaplasias of the gastrointestinal tract (intestinal metaplasia of the oesophagus and of the stomach, and metaplastic-hyperplastic polyposis of the colon, known to antedate neoplastic transformation), a subset of GMDs of unknown cause might be present in the duodenal mucosa before adenomatous changes ensue. That subset of GMD might have neoplastic proclivity similar to the metaplastic epithelium in other organs of the gastrointestinal tract. The known carcinogenic effect of high concentrations of bile acids and pancreatic juices bathing the duodenal mucosa carrying an irreversible subset of GDM might set aflame the adenomatous neoplastic transformation in these patients.
authors.affiliation: Gastrointestinal and Liver Pathology Research Laboratory, Department of Pathology Karolinska Institute and University Hospital, Stockholm, Sweden. carlos.rubio@ki.se
authors.forename: C A
authors.initials: CA
authors.lastname: Rubio
mesh_terms: D000236:Adenoma / Q000382:microbiology / Q000473:pathology*; D011125:Adenomatous Polyposis Coli / Q000382:microbiology / Q000473:pathology; D000368:Aged; D015331:Cohort Studies; D004379:Duodenal Neoplasms / Q000382:microbiology / Q000473:pathology*; D004386:Duodenum / Q000473:pathology*; D005260:Female; D016481:Helicobacter Infections / Q000150:complications; D016480:Helicobacter pylori; D006801:Humans; D007413:Intestinal Mucosa / Q000473:pathology; D008297:Male; D008679:Metaplasia / Q000382:microbiology / Q000473:pathology; D008875:Middle Aged; D011230:Precancerous Conditions / Q000382:microbiology / Q000473:pathology*