Gastric Heterotopia in the Duodenum

Abstract

Purpose: To characterize the endoscopic appearance and the clinical and histopathologic associations of gastric heterotopia (GH) in the duodenal mucosa. GH is an island of oxyntic glands lined by gastric epithelium lodged within the mucosa of the duodenum. Traditionally believed to appear endoscopically as elevated lesions, GHs have unknown clinical significance and are poorly characterized. Methods: We analyzed electronic data from Caris Diagnostics, a specialized gastrointestinal pathology group receiving specimens from endoscopy centers in 40 states. The database includes demographic and clinical information, a summary of the endoscopic findings, the site of origin, and the histopathologic report for each specimen. To identify the records for eligible duodenal biopsies, we extracted data from all cases with a sign-out date within the 12-month period from 4/01/07 to 3/31/08, and stored them in a Microsoft Access database. Statistical calculations were performed using SigmaStat 3.5 (Systat Software, Inc., Point Richmond, California); chi-square test, Student's t-test and Mann-Whitney Rank Sum Test were used as appropriate. A P value < 0.05 was considered significant. Results: There were 246,254 patient encounters with a total of 29,296 duodenal biopsies. GH was diagnosed in 527 biopsies (1.8%). For this analysis we selected the 20,646 unique patients (13,433 women or 65.0%) who had both gastric and duodenal biopsies available. Of these, 467 patients had GH: their median age was 59 years (range 16 to 92) and 246 (52.7%) were men. Thus men had a2-fold risk of having GH (O.R. = 2.11, 95% CI 1.76–2.54). The endoscopic impression of a duodenal polyp or nodule was reported in only 30 patients (6.4%) and duodenitis in 55 patients (11.8%); in the remaining endoscopic reports there was no mention of a specific lesion and specimens were submitted as “duodenal biopsy.” Histologically, only one of the 467 patients also had a flattened duodenal mucosa suggestive of celiac sprue; 3 subjects had concurrent duodenal intraepithelial lymphocytosis; and 9 patients had peptic duodenitis. The overall prevalence of H. pylori infection in the patient population was 12.0%: however, only 2.6% of GH patients H. pylori gastritis (P < 0.001); even fewer (9 patients or 1.9%) had gastric ulcer or erosions. In no case was H. pylori reported to infect the heterotopic gastric mucosa. Conclusion: The overwhelming majority of GHs are not submitted for pathologic examination with the endoscopic impression of a polyp or nodule, although it would seem likely that a lesion worth biopsying is usually seen. GH is twice as common in men as in women, is associated with a healthier-than-expected duodenum and stomach, and is not infected with H. pylori.