Gastritis

Gastritis is a broad term that includes a wide variety of non-neoplastic conditions of the gastric mucosa. The most widely used classification is the Updated Sydney System, which separates gastritis (characterized by inflammation) and gastropathy (mucosal aberrations with little or no inflammation). The most common cause of gastritis is H. pylori infection, which may cause antral-predominant non-atrophic inflammation (a risk factor for peptic ulcer) or atrophic pangastritis (a risk factor for gastric adenocarcinoma). Gastritides of unknown etiology include autoimmune gastritis (which leads to pernicious anemia), lymphocytic, and granulomatous gastritis. Amongst populations living in industrialized parts of the world the most prevalent gastric abnormality is reactive gastropathy. This is a histopathologic condition associated with chemical injury (most often caused by NSAIDs) characterized by epithelial regeneration, foveolar hyperplasia, and smooth muscle proliferation. Vascular abnormalities in the gastric mucosa and wall may cause hemorrhagic gastropathies, of which gastric antral vascular ectasia (GAVE), often associated with autoimmune disorders, is the best characterized. Hypertrophy of the oxyntic mucosa defines the hypertrophic gastropathies: Ménétrier's disease, a condition of unknown origin manifested by severe protein loss, and the Zollinger-Ellison syndrome, usually caused by a gastrin-secreting neuroendocrine tumor, which is associated with multiple recurrent refractory peptic ulcers.