S3685 A Case of Duodenal Polyposis

Abstract

Introduction: Duodenal polyps can be sporadic or associated with genetic conditions. Only a small percentage of duodenal polyps have malignant potential (Table). Hyperplastic polyps are often found in the colon but have rarely been described in the duodenum. Here, we present a case of numerous hyperplastic polyps found in the duodenum. Case Description/Methods: A 72-year-old male with a history of gastroesophageal reflux disease (GERD), colonic adenomas, and a family history of colon cancer presented with difficulty swallowing. He underwent laryngoscopy which was negative. He then underwent esophagoduodenoscopy (EGD). Numerous sessile polyps (2-15mm) were seen and biopsied in the second portion of the duodenum (Figure 1a). Pathology showed hyperplastic polyps (Figures 1b and 1c). We advised the patient undergo a repeat EGD in six months for surveillance given the number of polyps, and capsule endoscopy was also discussed to assess for polyps further along the small intestine. Discussion: The prevalence of duodenal mucosal tumors is estimated to be 4.6%. Non-neoplastic polyps include inflammatory polyps, Brunner’s gland hyperplasia, hyperplastic polyps, ectopic pancreatic mucosa, and hamartomatous polyps. Neoplastic polyps include adenomas, gastrointestinal stromal tumor (GIST), Brunner’s gland adenoma, carcinoid tumor, leiomyoma, lipoma, schwannoma, and serrated adenoma. Duodenal polyps may be associated with genetic disorders or inflammation, but most are sporadic. Less than 20 cases of duodenal hyperplastic polyps (HPs) have been described. Histology shows crypt serration with mucinous glands and goblet cells without cytologic atypia. Three types of HPs include microvesicular (most common), goblet-cell, and mucin-poor. Immunostaining shows patterns similar to colonic HPs. HPs (both colonic or duodenal) have been shown to have BRAF mutations in 75% of cases and KRAS mutations in 10%, and the proportion of each mutation depends greatly on location of the HP. Some case reports suggest HPs could be associated with inflammation, including one showing resolution of a duodenal HP after Helicobacter pylori (H. pylori) was eradicated. Many cases show associations with gastritis, peptic ulcer disease, and duodenitis as well. Duodenal HPs are not well characterized given their rarity and are likely benign lesions. At this time, patients with duodenal HPs should have follow up surveillance on a case-by-case basis considering family history, size and number of polyps, comorbidities, and associated symptoms.Figure 1:: Sessile duodenal polyps (2-15mm) (1A). Duodenal mucosa with slightly dilated crypts demonstrating a serrated or star shaped pattern with no cytologic atypia (Black arrows, H & E, 200x) (1B). Additional finding of a duodenal villous demonstrating an abrupt transition of the epithelium from normal epithelium on the left to a foveolar metaplastic epithelium on the right (H & E, 400x) (1C).Table 1:: Types of duodenal polyps, both non-neoplastic and neoplastic