Diagnosis of Early Gastric Cancer by Magnifying Endoscopy with NBI from Viewpoint of Histological Imaging: Mucosal Patterning in terms of White Zone Visibility and Its Relationship to Histology

The diagnosis of early gastric cancer by magnifying endoscopy with NBI is based on two components: microvascular pattern and mucosal pattern. Mucosal patterns are characterized by a whitish edge, which has been named the white zone. Some cancerous areas showing a distinct white zone form clear mucosal patterns, whereas others showing a nondistinct white zone do not form mucosal patterns. The aim of the present study was to clarify the histological differences between these two types of area. In transverse sections of gastric epithelium, the lengths of intervening parts in areas showing a distinct white zone, a nondistinct white zone, and an invisible white zone were measured, and the depths of the crypts in these three types of area were also measured. The intervening parts in areas with a nondistinct or invisible white zone were shorter than those in areas with a distinct white zone (P < 0.05), and the crypts in the former areas were shallower than those in the latter (P < 0.01). Areas in which the intervening part were long and the crypts deep tended to show a distinct white zone, whereas areas with short intervening parts or shallow crypts tended to show a nondistinct or non-visible white zone.