食道胃接合部腺癌のX線診断─X線造影検査の診断能と限界について

Radiographic Diagnosis for Adenocarcinoma of the Esophagogastric Junction

要旨●対象27例のX線造影像と切除標本の病理組織学所見を遡及的に見直し，食道胃接合部腺癌におけるX線造影検査の浸潤範囲診断能および深達度診断能を検討した．浸潤範囲診断能は66.7％（18/27例）であり，診断不成功例は，浸潤境界部に平坦な病変を随伴した病変が多く，食道胃接合部腺癌においても平坦病変に対するX線診断は限界となりうることが示唆された．側面像における陰影欠損のみをSM2以深の指標とした深達度診断は，感度57.1％（4/7例），特異度85.0％（17/20例），正診率77.8％（21/27例）であった．浅読み例の病理組織学所見は，いずれもSM垂直浸潤距離が短く，SM小浸潤は診断限界と考えられた．深読み症例は全例不十分な壁伸展による偽SM所見が誤診の要因であった．食道胃接合部腺癌のX線診断においては，閉鎖期，半閉鎖期の所見を加味して診断することが重要である．

　We retrospectively reviewed radiographic findings and histopathological findings of resected specimens from 27 selected patients, and investigated the diagnostic abilities of radiography on the range and depth of invasion in esophagogastric junction adenocarcinoma. The diagnostic performance on the area of invasion was 66.7%（18/27 cases）. Diagnostically unsuccessful cases frequently involved lesions accompanying flat lesions at the invasion edge, suggesting that radiographic diagnosis of flat lesions can be a limitation also for esophagogastric junction adenocarcinomas. When evaluating invasion depth, in which a filling defect in the lateral view was used as the sole indicator of SM2 or deeper invasion, the sensitivity, specificity, and accuracy were 57.1%（4/7 cases）, 85.0%（17/20 cases）, and 77.8%（21/27 cases）, respectively. Histopathological findings in underdiagnosed cases were characterized by a short SM vertical invasion distance; therefore, slight SM invasion was considered a diagnostic limitation. In all overdiagnosed cases, the misdiagnosis was caused by false SM findings due to insufficient wall extension. In radiographic diagnosis of esophagogastric junction adenocarcinomas, it is important to perform the diagnosis by taking into account closed phase and semi-closed phase findings.