3213 Giant Gastric Heterotopia (GH) in the Duodenal Bulb (DB): A Possible Cause of Gastric Outlet Obstruction (GOO)

Abstract

INTRODUCTION: The presence of gastric mucosa within the DB usually is an incidental finding during endoscopy and is seen in up to 8.9% of cases. While GH usually produces no symptoms, our patient presented with symptoms of GOO, which we attributed to the large size of the GH lesion, occupying >50% of the DB. This case of DH merits attention due to its uncommon appearance and presentation. CASE DESCRIPTION/METHODS: A 47-year-old woman with a history of insulin-dependent diabetes mellitus presented with abdominal pain, nausea, and post-prandial emesis for 1 year. Physical exam was normal, without a sucussion splash or post-prandial abdominal distention. Hematologic testing showed a Hb 9.8 mg/Dl. Other labs, including basic metabolic panel and liver biochemical tests, were normal. Abdominal CT without IV contrast was non-diagnostic. EGD identified a single polyp in the DB measuring 1.5 cm × 2 cm (Figure 1). Additionally, there was a more distal, irregular, cratered mass in the duodenum that was surrounded by a “carpet” of mucosal nodularity consistent with the appearance of Brunner's gland hyperplasia (BGH) (Figure 2). Both areas were biopsied. The pathology of the polyp showed gastric heterotopia (Figure 3) and the cratered mass showed peptic duodenitis. DISCUSSION: GH is seen throughout the adult GI tract but most commonly in the duodenum, with an incidence of 0.5% to 8.9%. 1 In most cases, GH causes no symptoms and is undiagnosed. When symptomatic, GH may cause abdominal pain from mucosal irritation secondary to the release of hydrochloric acid from parietal cells. Rarely, as in our patient, obstructive symptoms may be present. 2 For symptomatic patients, proton pump inhibitors (PPIs) are the cornerstone of treatment as they help to decrease acid secretion and, therefore, mucosal irritation. After EGD, our patient was started on a PPI and rapidly had symptomatic improvement. We suspect that her abdominal pain resolved due to decreased acidity within the DB, and that obstructive symptoms improved secondary to decreased inflammation within the DB. We present this case as a rare example of GOO caused by GH.