Micromucosal pattern in magnifying NBI

Micromucosal pattern of the region of interest was evaluated by magnifying NBI and it was categorized into foveola- and groove-types ¹⁵ . The foveola-type mucosa was characterized by round-to-oval, regular crypt openings and marginal crypt epithelium that was surrounded by a network of brownish subepithelial capillaries. Groove-type was defined as mucosa with brownish subepithelial capillaries encased in the crest of marginal crypt epithelium that was divided by continuous grooves of crypt openings (  Fig.2 ). According to proportion of foveola- and groove-type mucosa, micromucosal pattern in the region of interest was classified into > 80 % foveola, 50 % to 80 % foveola, 50 % to 80 % groove, and > 80 % groove type mucosa. The magnifying NBI has good interobserver agreement (κ > 0.75) for diagnosis of gastric mucosal pattern ²⁰ .

Two types of micromucosal patterns observed in magnifying narrow-band imaging (upper), and schematic diagram of these structures (lower). The foveola-type mucosa (left) was defined as round, regular crypt-opening (CO) and marginal crypt epithelium (MCE) surrounded by a network of brownish subepithelial capillaries (SEC). The groove-type mucosa (right) was defined as brownish SECs surrounded by ridged MCE.

All of the biopsy specimens were stained with hematoxylin and eosin. Mononuclear cell infiltration (inflammation), neutrophil infiltration (activity), glandular atrophy (atrophy), and intestinal metaplasia were estimated and graded as normal, mild, moderate or marked ¹ . The histological findings were evaluated by one pathologist who was unaware of the endoscopic findings.