Barrett食道癌の深達度診断

Diagnosis of the Invasion Depth for Barrett's Esophageal Adenocarcinoma

要旨●Barrett食道癌の深達度診断は白色光観察，EUS，X線造影検査で行う．深達度診断では白色光観察，EUSなどさまざまなモダリティでの所見を総合的に判断する必要がある．白色光観察による深達度診断は通常肉眼型，空気伸展の程度で行うが，食道胃接合部では管腔が狭く空気伸展の程度が判断しにくいので，肉眼型の所見を重視している．0-I型では，有茎性（0-Ip型），無茎性（広基性，0-Is型）で，大部分はT1b-SM2であるが，基部が細い場合にはT1a-Mの可能性もある．0-IIa型，0-IIb型はT1a-Mであるが，0-IIc型はT1a-MとT1b-SM2両方の場合があり，陥凹の深さ，陥凹内の性状を観察する．0-III型はその陥凹底が粘膜筋板を越えると推定される深い陥凹で，辺縁隆起を伴うことが多く，大部分はT1b-SM2である．食道胃接合部には，炎症に伴う線維化，固有食道腺，脈管，リンパ濾胞の存在などでEUSによる深達度診断が難しい場合がある．内部エコーの性状，エコーレベルの差異，周囲との層構造を注意深く観察する．

　The invasion depth of Barrett's esophageal adenocarcinoma is diagnosed using, endoscopic ultrasonography（EUS）, and X-ray contrast examination. A comprehensive diagnosis should be made by evaluating findings from multiple modalities such as WLI and EUS. Typically invasion depth is assessed using WLI, based on the degree of macroscopic appearance and air extension. However, because the lumen of the esophagogastric junction is narrow, macroscopic appearance is particularly important. Lesions classified as 0-Ip or 0-Is are mostly T1b-SM2. Lesions classified as 0-IIa and 0-IIb are T1a-M. While 0-IIc can be either orT1b-SM2 ; therefore, both the depth and the characteristics of the depression should be carefully examined. Lesions classified as 0-III are mostly T1b-SM2. At the esophagogastric junction, diagnosing invasion depth using EUS is challenging due to the presence of inflammation-related fibrosis, and proper esophageal glands, vessels, and lymph follicles. As a result, careful attention should be given to the characteristics of the internal echo, differences in echo levels, and the layer structure of the surrounding tissue.