By the endoscopic Congo red test, gastric polyps (104 cases) are classified into 3 types ; type 1) those located in the acid-secreting area and having acid-secreting activity, type 2) those located in the acid-secreting area, but having no acid-secreting activity, and type 3) those located in the nonacid-secreting area and having no acid-secreting activity. Type 1 polyps are not accompanied by fundal gastritis nor intestinal metaplasia. In three of 8 cases, polyps are numerous, and they are located only in the gastric body. They are not associated with polyposis of the colon and any ectodermal change. These polyps are hamartomas of the oxyntic gland ; the main histological abnormality is cystic dilatation of the oxyntic gland. In another 5 cases, one or two polyps are found in the gastric body. These polyps are hypertrophic mucosal tags of the oxyntic gland. Type 2 polype are accompanied by moderate or little fundal gastritis and intestinal metaplasia. However, polyps are not surrounded with intestinal metaplasia. In eight of 9 polyps, they are histologigically hyperplastic polyps. Another one polyp is a hamartoma of the pyloric gland ; the main abnormal histology is a downgrowth of cystically dilated pyloric glands. Type 3 polyps are found in 87 of 104 patients. They are accompanied by severe fundal gastritis and severe intestinal metaplasia. These polyps are surrounded with the intestinal metaplasia, and are histologically ATP or hyperplastic polyp.
