慢性胃炎粘膜（腸上皮化生）の拡大内視鏡所見

Magnifying Endoscopic Diagnosis for Chronic Gastritis and Gastric Intestinal Metaplasia

要旨●慢性胃炎や腸上皮化生の存在診断は胃癌のリスク層別化に重要である．また，胃癌を疑う病変の鑑別診断や癌の境界診断にかかわる背景粘膜の所見としても重要である．拡大観察により視認可能となる微小血管や微細表面構造に着目した胃炎分類が多数報告されている．Helicobacter pylori感染のない正常な胃底腺粘膜はfoveola typeの構造が観察されるが，萎縮・腸上皮化生が高度な慢性胃炎粘膜ではgroove typeの粘膜を認めるようになる．また腸上皮化生のNBI併用拡大観察ではLBC，WOS，marginal turbid band，ridge/villous patternなどの知見が報告されている．

　It is essential to diagnose chronic gastritis and gastric intestinal metaplasia to stratify the risk of gastric cancer. Lesions representing chronic gastritis and gastric intestinal metaplasia require a differential diagnosis from gastric cancer. Gastric cancer is typically characterized by the presence of mucosa surrounding it, which is associated with its boundary diagnosis. Many studies have reported gastritis classifications on the basis of microvascular patterns and microsurface structures using magnifying endoscopy with NBI（narrow-band imaging）. The normal gastric fundus gland mucosa without Helicobacter pylori infection has a foveola-type structure, whereas advanced chronic gastritis mucosa with severe atrophy and intestinal metaplasia has a groove-type structure. With the finding of intestinal metaplasia using magnifying endoscopy with NBI, several other findings such as a light-blue crest ; a white, opaque substance ; a marginal turbid band ; and a ridge/villous pattern have also been reported.