2022 Volume 64 Issue 1 Pages 43-49
A 70-year-old woman was referred to our department for further examination of a slightly elevated lesion (10 mm in size, with a depression at the top) located at the greater curvature of the antrum; the lesion was detected during a screening esophagogastroduodenoscopy. She had no history of Helicobacter pylori (H. pylori) eradication therapy, and the H. pylori IgG antibody titer was < 3 U/mL. The gastric mucosa showed no atrophy. Biopsy revealed tubular adenoma; however, magnifying endoscopy could not rule out the possibility of gastric cancer. Endoscopic submucosal dissection was performed with the patientʼs informed consent. Well-differentiated tubular adenocarcinoma was identified on histopathologic examination. Immunohistochemical staining was positive for CD10 and CDX2 and partially positive for MUC2, MUC5AC, and MUC6. This was a rare case of well-differentiated tubular adenocarcinoma with a predominantly intestinal phenotype pattern in the absence of H. pylori infection that developed in a mucosa without atrophy and intestinal metaplasia.
