<aside>

Atrophic gastritis is a chronic inflammatory disease of the gastric mucosa characterized by loss of gastric glands (atrophy), thinning of the mucosa, and replacement by intestinal-type epithelium or fibrous tissue.

</aside>

It is a premalignant condition, associated with gastric carcinoma and neuroendocrine tumors.

Etiopathogenesis

Autoimmune Atrophic Gastritis (Type A)

• Autoantibodies against parietal cells and intrinsic factor.
• Loss of parietal cells → achlorhydria + intrinsic factor deficiency → pernicious anemia (vitamin B12 deficiency).
• Predominantly affects fundus and body (spares antrum).
• Associated with other autoimmune diseases (thyroiditis, type 1 diabetes).

Multifocal Atrophic Gastritis (Type B)

• More common, usually due to chronic H. pylori infection.
• Patchy involvement of antrum and body.
• Progression: H. pylori gastritis → chronic atrophic gastritis → intestinal metaplasia → dysplasia → adenocarcinoma.
• Strong association with environmental factors (high salt diet, smoking).

Pathology

• Thinned mucosa with glandular loss.
• Intestinal metaplasia (goblet cells, absorptive epithelium).
• Inflammatory infiltrate: lymphocytes, plasma cells.
• Dysplasia may develop in long-standing cases.