Giant Inflammatory Pseudopolyp of the Duodenum

Abstract

Purpose: Duodenal polyps are an uncommon finding. Typically, duodenal polyps are frequently seen in patients with genetic syndromes such as familial adenomatous polyposis syndrome, but also may occur sporadically. Unless large enough to cause symptoms, duodenal polyps are often discovered incidentally on upper endoscopy. Once discovered, therapeutic management depends on patient symptoms, histology, and/or size of the polyp. Management may include observation, endoscopic removal, or surgery. Here, we present a case of an unusually large duodenal pseudopolyp with unique histological features. We describe the management and course of the polyp over a 3-year time period. A 59-year-old male with a past medical history significant for prior myocardial infarction, diabetes and hyperlipidemia was referred by his gastroenterologist for evaluation of a large 4 cm duodenal polyp (not involving the ampulla) that encompassed one half the circumference of his duodenal lumen. Approximately 2 weeks prior, he underwent an upper endoscopy for an upper gastrointestinal bleed (attributed to a small gastric vessel) at which time this large polyp was incidentally discovered. Review of outside pathology reports were concerning for an adenomatous polyp with low-grade dysplasia. Upon review of the biopsy specimen by a pathologist at our institution, the polyp was found to consist of benign small bowel mucosa with non-specific inflammatory and reactive epithelial atypia with no definitive dysplasia. Due to the concerning size of this duodenal polyp, the patient subsequently underwent an MRI and upper endoscopy. MRI revealed no extra duodenal involvement and once again, biopsy revealed benign duodenal mucosa with chronic inflammation and reactive changes with no dysplasia. Following these investigational tests, general surgery was subsequently consulted for recommendations concerning surgical management. Due to the benign histology of the polyp, conservative measures with close observation were recommended. Thus, a follow up EGD with EUS was performed 8 weeks later. EUS demonstrated slight involvement of the submucosa and histology revealed reactive and regenerative changes with no malignancy. The patient continued to have regular surveillance with five upper endoscopies over the past 3 years. His most recent endoscopy has revealed a significant reduction in polyp size with biopsy showing benign mucosa, normal villous architecture and no active inflammation. There has been no progression to dysplasia or malignancy. This case highlights an unusual finding of a giant inflammatory pseudopolyp with unique histological features and the role of conservative management.