[A case of Helicobacter pylori-negative depressed type gastric adenoma].

A 75-year-old woman was referred to our hospital for further examination of gastric antral abnormal endoscopic findings. Endoscopic study of the stomach revealed a depressed lesion in the gastric antrum. Atrophic findings were not recognized in the background gastric mucosa, and Helicobacter pylori infection was not detected by histology, an urea breath test, a rapid urease test and serological test. A diagnosis of adenoma was given histopathologically from the resected specimens. As a result of immunohistological study, the phenotype of the tumor was not classified as either gastric type or intestinal type. CDX2 was positive in part of the tumor.