Current Status and Challenges of Endoscopic Treatments for Duodenal Tumors.

Background: Superficial tumors of the duodenum, other than ampullary tumors, have been traditionally considered rare. However, reports of this kind of tumor have increased in recent times, and the demand for minimally invasive treatments have also increasing.

Summary: Adenomas and intramucosal carcinomas are target lesions for treatment. A preoperative diagnosis has not been established, but unnecessary biopsies increase the difficulty of treatment and should be avoided. Cold snare polypectomy, endoscopic mucosal resection (EMR), and underwater EMR are treatment options for small lesions. Endoscopic submucosal dissection enables secure resection even for large lesions, but it is technically demanding and associated with a higher complication rate. After endoscopic resections, exposure of digestive juices is believed to cause delayed complications. To prevent these complications, several closing and covering methods are proposed, with favorable clinical results. Key message: A treatment method should be chosen based on each patient's situation. With any of the treatment methods, post-resection measures are required to prevent delayed complications. Secure closure of resection wounds seems promising.