A 49-year-old woman has a history of peptic ulcer disease for which she has been treated with proton pump inhibitors. She has had nausea with vomiting for the past 2 months. Upper GI endoscopy reveals three circumscribed, round, smooth lesions in the gastric body from 1 to 2 cm in diameter. Biopsies are taken and microscopically show the lesions to consist of irregular glands that are cystically dilated and lined by flattened parietal and chief cells. No inflammation, Helicobacter pylori, metaplasia, or dysplasia is present. What is the most likely diagnosis?

There is an association of fundic gland polyps with the use of proton pump inhibitors and also with familial adenomatous polyposis (FAP); increased gastrin may drive glandular hyperplasia. Gastric adenomas are most common in the antrum, have intestinal metaplasia with dysplasia, and are precursors to adenocarcinoma; they may occur with FAP. Hyperplastic polyps are associated with chronic gastritis, often from H. pylori infection. One form of hypertrophic gastropathy is Menetrier disease, which results from excessive secretion of transforming growth factor-alpha (TGF-a) with diffuse enlargement of gastric rugae and protein-losing enteropathy.