Topographic differences in gastric micromucosal patterns observed by magnifying endoscopy with narrow band imaging

Background and Aim: The distributions and grades of Helicobacter pylori induced gastritis are known to vary among H. pylori-associated diseases. The aim of this study was to investigate the differences in distributions of gastric micromucosal structures observed by magnifying narrow band imaging (NBI) endoscopy among patients with different H. pylori-associated diseases. Methods: Ninety-five patients with active duodenal ulcers (n=24) and diffuse-type (n=24) and intestinal-type (n=47) early gastric cancers were enrolled. The magnified NBI findings were evaluated at the lesser and greater curvatures in the upper gastric corpus and were classified according to the modified A-B classification system. Biopsy specimens were also evaluated. Results: In a total of 190 areas observed with magnifying NBI, histological grading (inflammation, activity, atrophy and intestinal metaplasia) showed significant differences among the classified micromucosal patterns (P<0.001). Types B-1 and B-2, with mild atrophic changes and few areas of intestinal metaplasia, were seen mostly in the duodenal ulcers group. Types B-3 and A-1, with moderate atrophic changes, were seen in the diffuse-type early gastric cancers at the lesser curvature. Types A-1 and A-2, with severe atrophic change and a high frequency of intestinal metaplasia, were seen in the intestinal-type early gastric cancers at the lesser curvature. The prevalence of micromucosal structures differed significantly among the three groups both at the lesser and greater curvatures (P<0.001). Conclusions: Magnifying NBI endoscopy clearly revealed detailed micromorphological differences corresponding to the histology and endoscopic findings among patients with different H. pylori-associated diseases.