A case of non-ampullary duodenal adenoma showing whitish color changes during potassium-competitive acid blocker treatment.

A 71-year-old male presented with suspected gastric cancer during screening. Esophagogastroduodenoscopy (EGD) revealed a slightly decolored flat lesion (diameter: 5 mm) on the duodenal bulb (Fig. 1a). On magnifying endoscopy with narrow-band imaging (M-NBI), meandering microvessels were visualized (Fig. 1b). This article is protected by copyright. All rights reserved.