Endoscopic Treatment for Superficial Nonampullary Duodenal Tumors.

Superficial nonampullary duodenal epithelial tumors are considered rare but have been increasingly recognized in recent years. Accordingly, the importance of endoscopic treatment for the lesions are also increasing. An endoscopic resection can be considered for duodenal adenoma and mucosal cancer. The choice of resection method should be made based on the size of the lesion, endoscopic findings, pathologic diagnosis, and risk of procedure-related complication. For small adenomas <10 mm in size, endoscopic mucosal resection (EMR), cold snare polypectomy, and underwater EMR can be considered. An en bloc or piecemeal resection using EMR or underwater EMR can be selected for 10-20 mm sized adenomas. For lesions ≥20 mm in size or suspicious for mucosal cancer, an endoscopic submucosal dissection followed by closure of the mucosal defect conducted by an experienced endoscopist is appropriate.