大腸sm癌における浸潤度の臨床診断精度―拡大内視鏡診断を中心に

Clinical Assessment on Accuracy of Invasion Depth of Submucosally Invasive Colon Cancer Predicted by Magnifying Colonoscopy

要旨　拡大内視鏡を用いたpit pattern診断によって内視鏡診断は病理組織診に近づいてきた．また内視鏡治療の機器，技術の進歩に伴い内視鏡治療の適応範囲を決めることがますます重要になってきている．われわれの施設では工藤らの相対分類を用いて良い成績をあげているが，今回は大腸癌取扱い規約に今後掲載予定となっている垂直浸潤距離1,000μmという基準について拡大内視鏡の視点から検討した．結果，平坦型および陥凹型についてはV_N pit pattern が垂直浸潤距離1,000μm以上のsm癌の指標になると思われたが，隆起型の病変についてはV_N pit patternではない病変でも1,000μmを超えて浸潤しているものが多数認められたためV_I型の中でsm深部浸潤している病変の指標については今後検討を続けていく必要があると思われた．

　Due to pit pattern analysis by magnifying endoscopy, an endoscopic diagnosis is becoming almost as good as histopathological diagnosis. With advancements in endoscopic equipment and techniques we are forced to be even more careful about the indications for endoscopic treatment. We have been quite successful in pretreatment diagnosis of colon cancer patients by means of the relative grading system of submucosal invasion (Kudo, et al.). Since 1,000μmof directly measured invasion depth is expected to be used as one of the rules for colon cancer diagnosis, we have checked the validity of the direct measurement of invasion depth from the magnifying endoscopic point of view.

　In case of flat or depressed type, almost all lesions with VN pit pattern have invaded deeper than 1,000μm. However, in case of the elevated type, there was a significant number of lesions with VI pit pattern with invasion depth of over 1,000μm.

　1) Digestive Disease Center, Showa University Northern Yokohama Hospital, Yokohama, Japan