食道小扁平上皮癌の深達度診断―超音波内視鏡（endoscopic ultrasonography；EUS）

Depth of Superficial Esophageal Cancer Invasion Shown by Endoscopic Ultrasonography (EUS)

要旨　超音波内視鏡（EUS）は細径プローブによる直視下に腫瘍を確認，流水下で行う．T1a-EPは内視鏡，拡大内視鏡所見を優先する．T1a-LPMはEUSで正確に診断できるため，迷った場合は，第4層の低エコー層（粘膜筋板）を描出し，これを基準として診断する．T1a-MM～SM1もEUSは有用である．SM2は内視鏡による表面からの診断に限界があるため，EUSの判定は正確で，特にSM3との鑑別に有用である．

　Method : A high frequency ultrasonic probe was passed through the endoscopic channel. Scanning was performed at the site of the endoscopic finding when the lesions were covered with water. T1a-EP cancer was diagnosed by endoscopic findings or magnified endoscopic findings better than by EUS. T1a-LPM was also diagnosed by magnified endoscopic findings, but EUS also gave precise diagnoses by delineating the muscuralis mucosea. The diagnoses of T1a-MM and T1b-SM1 by EUS were good. EUS especially gave better results in the differential diagnosis between T1b-SM2 and T1b-SM3.