FIGURE 1.

Underwater endoscopic mucosal resection (EMR) for a superficial non‐ampullary duodenal epithelial tumor (SNADET). (a) A 15 mm‐flat elevated lesion is located on descending part of the duodenum. (b, c) The lesion was captured by a snare after filling the lumen with normal saline. (d) The lesion was resected in a single piece without any adverse events. (e) The mucosal defect was completely closed using endoclips. (f) Resected specimen. Pathological findings revealed low‐grade adenoma with free horizontal and vertical margins