The Endoscopic Diagnosis of Superficial Non-Ampullary Duodenal Epithelial Tumors Using White Light Imaging

The recognition of superficial non-ampullary duodenal epithelial tumors (SNADETs) has increased with advancements in endoscopic technology and increased awareness among clinicians. White light imaging (WLI) remains the primary diagnostic modality for SNADETs. However, data for standardized endoscopic diagnostic approaches are lacking.

SNADETs are typically identified by their whitish, flat-elevated appearance and are predominantly located in the descending duodenum. The whitish mucosa is referred to as milk white mucosa (MWM). Although biopsies are traditionally performed for the diagnosis, biopsies have limited sensitivity for histological grading and may cause submucosal fibrosis, which complicates subsequent endoscopic resection. SNADETs are classified as gastric, gastrointestinal, or intestinal mucin phenotypes. Gastric SNADETs are usually found in the pre-ampullary region and are typically lacking MWM, whereas intestinal-type SNADETs often exhibit MWM. Several endoscopic features under WLI, such as lesion color, size, surface depression, and morphology, are useful for predicting the grade of dysplasia. Features such as a submucosal tumor-like appearance, deep depression, and oral side location are important for assessing submucosal invasion.

WLI plays an important role in the detection and initial assessment of SNADETs. Although differentiating SNADETs from other duodenal lesions using WLI alone remains challenging, understanding the endoscopic features associated with each mucin phenotype aids in accurate distinction of high-grade dysplasia from low-grade dysplasia. Future studies are warranted to establish a comprehensive endoscopic diagnostic system for SNADETs.