Background and Objective: Polypoid duodenal lesions are rarely encountered during routine upper endoscopy, but endoscopic resection of duodenum neoplasia can be complex and challenging. In this narrative review, we aim to summarize the current literature regarding the multitude of duodenal lesions, review the current literature regarding the various approaches and techniques for endoscopic resection of duodenal lesions, highlight the associated potential adverse events and complications, and identify areas in which additional studies are needed. Methods: PubMed was used to search for all reviews and studies regarding duodenal lesions and duodenal resection written in the English language through September 2023. Key Content and Findings: Compared to the colon, the duodenum is relatively fixed in position, has a narrower lumen, and the walls are thinner and hypervascular, all of which increase the difficulty and risk of endoscopic resection. It is critical to first understand a duodenal lesion's layer of origin and if there is papillary involvement before attempting any resection. Conventional endoscopic mucosal resection (EMR) techniques are the standard approach for most non-ampullary duodenal lesions >= 10 mm, but underwater EMR may reduce the risk of perforation and increase the rate of en bloc resection. Advanced resection techniques-like cap-assisted EMR or full thickness resection-should be limited to high-volume centers with experienced endoscopists. Endoscopic submucosal dissection is very challenging in the duodenum, and even when successfully performed by experts, delayed bleeding and delayed perforation can occur. Conclusions: Duodenal polyp resection is associated with higher complication rates and is typically more challenging than resection of similar lesions in the colon, and understanding the nuances of the duodenum and the various approaches to endoscopic resection is critical to a successful, safe procedure. Future work is needed to refine optimal resection technique to reduce and manage recurrent duodenal lesions as well as surveillance intervals following resection.
