Early Gastric Cancer Detected During 15‐year Surveillance After Ménétrier Disease Remission and Successfully Treated With Endoscopic Submucosal Dissection: A Case Report

antibody test and urea breath test yielded negative results. Remission was achieved with steroid therapy, and she was relapse-free with the use of a proton pump inhibitor. Annual esophagogastroduodenoscopy (EGD) was continued for gastric cancer surveillance. Fifteen years after the diagnosis of MD, a type 0-I well-differentiated tubular adenocarcinoma was detected on the posterior wall of the upper gastric body. EGD, computed tomography, and endoscopic ultrasonography revealed no findings suggestive of MD recurrence, and the lesion was considered intramucosal. Endoscopic submucosal dissection resulted in curative en bloc resection. Histopathology revealed no evidence of active MD. The patient remained free of MD relapse and gastric cancer recurrence. MD is characterized by giant gastric folds and protein-losing gastroenteropathy, and it is considered a risk factor for gastric cancer. However, reports of gastric cancer diagnosed at an early stage and treated endoscopically during long-term follow-up after clinical remission induced by medical therapy, as in the present case, are rare. This case highlights the importance of continued endoscopic surveillance for gastric carcinogenesis even after long-term clinical remission of MD.