Foveolar Gastric Metaplasia of the Duodenum: A Frequent, so far Neglected Type of Duodenal Polyp

Abstract

Foveolar gastric metaplasia of the duodenum (FGM) is considered as imperfect mucosal healing in the context of H. pylori gastritis and intake of NSAIDs or ASS. Typical endoscopic findings are redness of the mucosa, erosion/ulcer and loss of mucosal folds. During diagnostic histological examinations we observed a frequent so far not described association of FGM with endoscopically observed duodenal polyps. The archives of two institutes of pathology with high gastroenterological workload (approximately 100 000 patients per year) were investigated for an association between "duodenal polyp" and "foveolar gastric metaplasia". In Institute 1, of 481 duodenal polyps 41 % were classified as FGM, 9 % as adenoma and 2 % as heterotopic gastric mucosa. In 48 % no histological correlate was present. In Institute 2, 217 cases of FGM were diagnosed. Of these, in 69 cases the endoscopic finding was "polyp" (32 %). In the other cases, the endoscopic findings were mucosal defect (18 %), redness/inflammation (16 %), suspicion for gastric heterotopia (5 %) and scar (3 %). In 26 % of cases no pathologic endoscopic finding was reported. Both groups of patients with FGM showed a similar distribution of age ranges (24 - 83 years and 16 - 88 years), median age (62 years and 61 years, respectively) and a dominance of male sex (both 1.5:1). In conclusion, foveolar gastric metaplasia is a frequent, so far neglected correlate of endoscopically detected duodenal polyps.