CLINICAL FEATURES AND ENDOSCOPIC FINDINGS OF AUTOIMMUNE GASTRITIS AND RESULTANT GASTRIC TUMOR

Abstract

Autoimmune gastritis (AIG) is a special type of gastritis in which parietal cells are destroyed due to autoimmune abnormalities such as anti-parietal cell antibodies that are produced against the proton pump (H^＋/K^＋ ATPase) in the process. AIG is characterized by reverse atrophy on endoscopy. In addition, findings such as sticky adherent dense mucus, remnant oxyntic mucosa, and circular wrinkle-like patterns in the antrum can be observed. Endoscopic images of early-stage AIG obtained from recent reports have shown features such as longitudinal reddish pseudopolyp-like nodules, thickened and edematous mucosa, and mosaic-like patterns of the pits on the greater curvature of the corpus.

Gastric cancer complicated with AIG is an early intestinal cancer that is located mainly in the L to M region. The serum gastrin level and prevalence of pernicious anemia were higher in gastric cancer cases complicated with AIG than in non-gastric cancer AIG cases. Furthermore, histological analysis of the background gastric mucosa in gastric cancer cases complicated with AIG revealed severe atrophy and mild mononuclear infiltration compared with non-gastric cancer AIG cases.

Gastric neuroendocrine tumors complicated with AIG were classified as type I by Rindi et al. These tumors, located in the corpus, have a small diameter and are accompanied by hypergastrinemia. They have a good clinical prognosis. The predominant colors in the tumor are pale yellow and red. Dilated vessels, redness, and depressions may be observed in the center of the tumor.