Endoscopic features of nonampullary duodenal tumors with narrow-band imaging.

Endoscopic features of nonampullary duodenal adenomas and early adenocarcinomas are not well known. The aims of this study were to investigate the endoscopic features of the tumors using conventional endoscopy and narrow-band imaging magnified endoscopy, and to reveal the relationship between the endoscopic features and histological grades.The study included 24 nonampullary duodenal adenomas and early adenocarcinomas in 22 patients who underwent conventional endoscopy and narrow-band imaging magnified endoscopy. The tumors were divided into histological groups according to the modified Vienna classification system.The 24 tumors were 17 adenomas and 7 carcinomas in situ, and divided into 10 Category 3 and 14 Category 4 lesions. On conventional endoscopy, 22 of the 24 (92%) lesions, had a milk-white mucosa and the frequency of a marginal-type one was significantly higher for the Category 4 group (p = 0.028). On narrow-band imaging magnified endoscopy, all tumors had a heterogeneous pattern. The frequency of an obscure mucosal pattern and a network microvascular pattern was significantly higher for the Category 4 group (p = 0.024 and 0.001, respectively).Narrow-band imaging magnified endoscopy following conventional endoscopy might be a promising approach to realizing lesions or predicting histological grade of nonampullary duodenal intraepithelial tumors.