Novel Magnifying Endoscopic Classification for Early Gastric Cancer with Narrow Band Imaging System; Particularly Focusing On Micro-Vascular Pattern and Surface Glandular Structure

Abstract

Background and Aim: Abnormal microvascular pattern for differentiated type adenocarcinoma in the stomach was firstly reported by Yao K et al. Nakayoshi et al. also reported magnifying endoscopic classification of fine network pattern(FNP) and corkscrew pattern(CSP) mainly based upon microvascular pattern. In this study we introduced a newly designed NBI magnifying endoscopic classification. Two additional patterns of intra-lobular loop pattern-1(ILL-1) and intra-lobular loop pattern-2(ILL-2) were added in this novel classification with further assessment of superficial glandular structure. We report actual diagnostic rate of new categories (ILL-1 and ILL-2) and its clinical impacts. Patients and Methods: From June 2006 to September 2008, 257 lesions in 240 cases of early gastric cancer (223 lesions of differentiated type, 34 lesions of poorly differentiated type) were enrolled in this study. Novel NBI magnifying endoscopic classification: NBI magnifying images were classified into four categories based on abnormal microvascular pattern and irregularity of superficial glandular structure (Figure). FNP has small glandular opening to mucosal surface with abnormal mesh-like microvascular structure. Microvascular structure encircles each glandular opening. ILL-1 has villous glandular structure with loop like microvessels in it. In ILL-2, villous glandular structure was started to be destructed. In CSP almost all glandular structures have been disappeared with marked appearance of corkscrew-like abnormal vessels. Results: Among 223 lesions of differentiated type adenocarcinoma, FNP, ILL-1, ILL-2, and CSP were observed respectively in 35 lesions (15.7%), 133 lesions (59.6%), 54 lesions (24.2%), and 1 lesion (0.5%). Differentiated-type adenocarcinoma mainly demonstrated FNP and ILL with the exception of one lesion. More than 80% of differentiated type adenocarcinoma were classified into ILL-1 and ILL-2. Among 34 lesions of poorly differentiated type adenocarcinoma, ILL-2, CSP were observed respectively in 14 lesions (41.2%), 20 lesions (58.8%). Poorly differentiated type adenocarcinoma were all classified in ILL-2 and CSP. Conclusions: Novel NBI magnifying classification included ILL pattern may predict the histological subtype of gastric carcinoma.