拡大内視鏡による胃炎，腺腫，胃癌の鑑別診断

Differential Diagnosis of Gastric Cancer, Gastric Adenoma, and Gastritis by Magnifying Endoscopy

要旨●VSCS（VS classification system）を用いたNBI併用拡大内視鏡（M-NBI）による胃癌の質的診断能は極めて高く，精密検査のみならず，胃ルーチン検査にM-NBIを導入するメリットは大きい．すなわち，通常内視鏡検査で同定した病変について引き続き高い診断能をもって質的診断が可能である．また不要な生検を省略できる点でも有用である．さらに近年，病理組織像に迫るM-NBIの新知見が相次いで報告されており，VSCSの補助的な所見として注目されている．VSCSを習得するためには，“目”のみならず“手”のトレーニングも重要である．最大倍率を含む一定の観察条件で病変を観察することが，VSCSの高い客観性と再現性をもたらすことを理解するべきである．

　M-NBI（magnifying endoscopy with narrow-band imaging）using the VSCS（vessel plus surface classification system）is very useful for the accurate diagnosis of early gastric cancer. Significant benefits can be achieved when M-NBI is applied not only in preoperative examination but also in screening endoscopy. The use of M-NBI in screening endoscopy is associated with excellent real-time diagnostic performance and accurate endoscopic diagnosis of early gastric cancer. M-NBI may also contribute to reducing the number of biopsies required to detect one early gastric cancer. Recent reports have described various novel endoscopic markers visualized by M-NBI that can predict specific histopathological findings. The presence of these novel endoscopic markers can be an adjunct to diagnosis using M-NBI with VSCS. Training is required for both interpreting endoscopic images and developing skills for obtaining maximal resolution ; this will improve the diagnostic ability of the operator using M-NBI with VSCS. Diagnosis using M-NBI with VSCS may provide excellent diagnostic performance with high confidence and good reproducibility to the endoscopist if M-NBI is performed under consistent conditions, including observation under maximal magnification.