2025 Volume 67 Issue 3 Pages 214-219
Upper gastrointestinal endoscopy identified an erythematous, depressed lesion in the lower gastric body of a 71-year-old Japanese male who had previously undergone curative resection for early gastric cancer 16 years ago, along with Helicobacter pylori eradication. Following biopsy confirmation of adenocarcinoma, ESD was performed, revealing a well-differentiated tubular adenocarcinoma (tub1) located in the mucosa, with submucosal ectopic gastric glands immediately beneath it.
The majority of these ectopic gastric glands exhibited no cytological atypia; however, a small focus of tub1 was detected within the ectopic glands. Immunohistochemistry demonstrated that intramucosal tub1 exhibited an intestinal phenotype, whereas ectopic glands, including focal tub1, displayed a gastric phenotype.
To the best of our knowledge, this case is the first reported instance of ESD-resected early gastric cancer indicating the coexistence of phenotypically distinct intramucosal tub1 and focal tub1 within the submucosal ectopic gastric glands.
