ENDOSCOPIC DIAGNOSIS OF SUPERFICIAL NON-AMPULLARY DUODENAL EPITHELIAL TUMORS

Abstract

The diagnosis of superficial non-ampullary duodenal epithelial tumors (SNADET), defined as adenomas and mucosal or submucosal adenocarcinomas, is increasingly common due to the widespread use of screening EGD. Most SNADETs are diagnosed in the first and second parts of the duodenum around the papilla of Vater. Diagnosis based on white-light endoscopy and image-enhanced endoscopy with magnification helps differentiate tumors from non-tumors, assessing tumor histological grade (e.g., low-grade adenoma [LGA] vs. high-grade adenoma or adenocarcinoma [HGA/Ca]), and identifying epithelial subtypes (e.g., gastric vs. intestinal). Gastric epithelial subtypes account for 10-20% of SNADETs and exhibit a higher histological grade than intestinal types. Tumor-like lesions located in the duodenal bulb can sometimes be difficult to distinguish between tumors and non-tumors, requiring comprehensive evaluation, including biopsy and endoscopic ultrasonography. For optimal treatment selection of SNADETs, differential diagnosis between LGA and HGA/Ca, considering the epithelial phenotypes, is crucial.