早期胃癌の深達度診断─超音波内視鏡検査

Endoscopic Ultrasonographic Diagnosis ofEarly Gastric Cancer Invasion Depth

要旨●EUSによる正常胃壁の基本層構造と早期胃癌深達度診断の基本について述べ，さらに早期胃癌のEUS診断能について検討した．過去5年間に当センターで切除された早期胃癌1,601病変のうち，EUSが施行された568病変の描出不良率は11.6％（66病変）であった．また，描出不良例を除いた502病変でEUSおよび内視鏡検査の深達度診断能を肉眼型，深達度別に検討した．その結果，描出不良率はL領域で高かった．描出可能な病変では，EUSは7.2％で内視鏡診断の不一致を補正するのに有用であり，oversugeryを避ける観点からは，特に内視鏡診断SM2の病変にEUSを施行するのが有用と考えられた．

　We evaluated the ability of EUS（endoscopic ultrasonography）for diagnosing early gastric cancer invasion depth. We studied 875 lesions using EUS and were unable to visualize clear images for 99 lesions（11.3%）. The lesions we were unable to visualize by EUS were particularly high in the L region. Furthermore, among the 776 lesions with clear EUS images, we were able to accurately determine the early gastric cancer invasion depth of 40 lesions（5.2%）, which were misdiagnosed by conventional endoscopy.

　In conclusion, EUS is useful for lesions, which were diagnosed as submucosal 2 lesions by conventional endoscopy, to avoid unnecessary surgery.