Gastric heterotopia-like duodenal polyps containing Brunner glands with abundant paneth cells and oxyntic cells are frequently associated with advanced left-sided colorectal polyps

Abstract

Duodenal polyps mimicking gastric heterotopia but with abundant Paneth cells and occasional oxyntic cells in deep Brunner glands are difficult to classify, and the clinical significance of identifying these lesions is currently unknown. We report herein clinicopathological features of six of these lesions that arose in four patients. There were equal numbers of male and female, with an average age of 67. The average size of the polyps was 4.3 mm. All four patients had concurrent colorectal adenomatous polyps including two patients with giant left-sided tubulovillous adenomas measuring 55 mm and 44 mm. One patient had two left-sided traditional serrated adenomas. More than 10 gastric fundic gland polyps were found in two patients and one had a gastric hyperplastic/hamartomatous polyp. None of the patients had a known gastrointestinal polyposis syndrome. Histologically, all six lesions were characterised by a mixture of both gastric foveolar-type and small intestinal-type surface epithelium with deep Brunner glands containing abundant Paneth cells and occasional gastric oxyntic cells. Duodenal polyps mimicking gastric heterotopia but with abundant Paneth cells and oxyntic cells in deep Brunner glands are frequently associated with advanced left-sided colorectal polyps. Identifying such lesions in the duodenum may warrant a colonoscopy to rule out concurrent significant colorectal lesions.