Gastric Cancer - Intestinal Metaplasia - Endoscopy (6 of 7)

Chronic gastritis is a histopathologic entity characterized by chronic inflammation of the stomach mucosa. Gastritides can be classified based on the underlying etiologic agent (eg, Helicobacter pylori, bile reflux, nonsteroidal anti-inflammatory drugs [NSAIDs], autoimmunity, allergic response) and the histopathologic pattern, which may suggest the etiologic agent and clinical course (eg, H pylori –associated multifocal atrophic gastritis) Other classifications are based on the endoscopic appearance of the gastric mucosa (eg, varioliform gastritis) Although minimal inflammation is observed in some gastropathies, such as those associated with NSAID intake, these entities are discussed in this article because they are frequently included in the differential diagnosis of chronic gastritis. Chemical or reactive gastritis is caused by injury of the gastric mucosa by reflux of bile and pancreatic secretions into the stomach, but it can also be caused by exogenous substances, including NSAIDs, acetylsalicylic acid chemotherapeutic agents, and alcohol. These chemicals cause epithelial damage, erosions, and ulcers that are followed by regenerative hyperplasia detectable as foveolar hyperplasia, and damage to capillaries, with mucosal edema, hemorrhage, and increased smooth muscle in the lamina propria.