Gastric pathology associated with Helicobacter pylori

This article discusses the history of Helicobacter infection and the histology of the normal stomach. The author examines the specific histological features related to Helicobacter pylori infection, including leukocyte infiltration of the epithelium, specific epithelial changes, and the morphology and distribution of the bacteria. Nonspecific changes, including atrophy, metaplasia, and stromal damage, are reported. Finally, the author describes special features: electron microscopy; changes after treatment; duodenal ulcer; other related conditions, including neoplasia; quantification of the histology; and the Sydney and Houston classifications.