Guideline sources The following summarized guidelines for the evaluation and management of non-ampullary duodenal adenoma are prepared by our editorial team based on guidelines from the European Society of Gastrointestinal Endoscopy (ESGE 2021). 1 Guidelines 1. Diagnostic procedures Lower gastrointestinal endoscopy: perform a colonoscopy in patients with duodenal adenoma, if not performed yet. B Upper gastrointestinal endoscopy: use a cap-assisted method if the location of the minor and/or major papilla and their relationship to a duodenal adenoma is not clearly established during forward-viewing endoscopy. B Show 2 more Biopsy: consider performing biopsy for histological assessment before endoscopic resection if endoscopic features are suggestive of superficial duodenal adenoma, since its additional diagnostic yield might be limited and resection might be compromised. C 2. Therapeutic procedures https://web.pathway.md/diseases/reccL0tReAHqPiqRQ 1/2 6/30/23, 1:17 AM Non-ampullary duodenal adenoma Pathway Endoscopic resection: consider performing endoscopic resection of all duodenal adenomas as progression to invasive carcinoma is highly likely. B Show 7 more Endoscopic ablation: recognize that an additive role for ablative or other tumor-destruction techniques is minimal of lack of efficacy. B 3. Follow-up and surveillance Endoscopic surveillance: perform endoscopic surveillance 3 months after the index treatment. Perform follow-up endoscopy 1 year later in patients with no recurrence. Adapt the surveillance intervals thereafter to the lesion site, en bloc resection status, and initial histological result. B Management of recurrent disease: Consider performing endoscopic resection, if feasible, in patients with recurrences after endoscopic treatment for superficial non-ampullary duodenal lesions, in the absence of suspected malignancy. B Consider leaving the choice of endoscopic technique for the management of recurrent adenoma to the discretion of the endoscopist, according to the morphology of the lesion and patients characteristics. C References 1. Geoffroy Vanbiervliet, Alan Moss, Marianna Arvanitakis et al. Endoscopic management of superficial nonampullary duodenal tumors: European Society of Gastrointestinal Endoscopy ESGE Guideline. Endoscopy. 2021 May;53 5 522 534. Open https://web.pathway.md/diseases/reccL0tReAHqPiqRQ 2/2