A case of early autoimmune gastritis with characteristic endoscopic findings.

Significant atrophic gastritis in the fundic gland region is a well-known endoscopic finding observed in autoimmune gastritis (AIG). The endoscopic features of early AIG have not been reported. Iron deficiency, vitamin B12 deficiency, anemia, or neurological symptoms may not be observed in the early stages of AIG, and it may thus be difficult to diagnose early AIG based on clinical findings. We treated a 50-year-old Japanese female whose condition was suspected to be early AIG. The endoscopic findings showed normal gastric pyloric gland mucosa, and diffuse reddened and edematous gastric fundic gland mucosa. Pathologically, local infiltration of lymphocytes and decrease of parietal cells was present in a deep part of the gastric fundic gland mucosa. Blood tests showed that the titer of parietal cell antibody (PCA) was 1:320 and the gastrin level was 820 pg/ml. We determined that the patient had AIG because she also had Hashimoto's disease, the PCA titer was high, the serum gastrin level was slightly increased, and inflammation was observed only in the gastric body on the endoscopic images. To the best of our knowledge, this is the first case report of endoscopic findings that suggest early AIG, before atrophic changes were observed.