胃粘膜の拡大観察―微小病変の良悪性診断

Magnifying Endoscopic Findings of Gastric Mucosa―Differential Diagnosis of Minute Lesions

要旨　拡大内視鏡検査により胃粘膜表面の微細模様と微細血管が観察可能である．特に，粘膜微細血管の観察能においては，他の診断手段と比べて内視鏡検査に優位性がある．胃炎に伴う微細な変化を認識することで，より正確な発赤病変の良悪性診断ができるようになる．胃炎に伴う発赤の拡大内視鏡診断においては，不整を伴わないcapillary networkの拡張所見が大切である．発赤型の分化型胃癌の拡大内視鏡診断では，周囲粘膜との明瞭な境界を認めること，発赤部位に異常な微細血管を捉えることが重要である．拡大内視鏡による診断学は今後のさらなる発展が期待できる．

　The observation of gastric surface mucosa using magnifying endoscopy is aimed at detecting microsurface structure and microvascular architecture of the mucosa. Microvascular architecture of the mucosa includes the normal microvascular system and tumorous microvessels. Magnifying endoscopies have the advantage of clearly visualizing the microvascular architecture of the mucosa. It is useful for diagnosis of early-stage gastric cancer to clarify the minute morphological changes of erythematous gastritis. The typical appearance of erythematous gastritis seen under magnifying endoscopy is varied dilatation of the capillary network surrounding the necks of gastric pits. The superficial-depressed type of differentiated gastric cancer reveals a well-demarcated area and proliferating irregular microvessels. Magnifying endoscopic observation of microvessels may be helpful for the identification of early-stage gastric cancer, so it is necessary that endoscopists establish as soon as possible the diagnostics of microvessels of the mucosa, based on magnifying endoscopic observation.