粘膜下腫瘤型（0-Isep）を示した食道上皮内癌の1例

Intraepithelial Carcinoma Mimicking Subepithelial Type (0-lsep), Report of a Case

要旨　患者は58歳，女性．原爆に被爆．内視鏡では切歯より29～32cmの食道右側壁に立ち上がりのなだらかな，高さが2～3mm程度の隆起性病変があり，病変の口側では縦長の白苔が付着したびらんが2個存在し，その肛門側に発赤が認められた．白苔，発赤に一致してヨードに不染であった．X線では小顆粒状の透亮像の集簇所見があり，壁伸展不良，壁不整などの所見を認めなかった．病理組織所見は0-Ⅱa，深達度epで，癌は周辺の上皮より0.1～0.2mm厚いのみで，粘膜固有層に軽度の線維化や，胚中心が目立つリンパ濾胞の形成があり，更に周囲の粘膜下層では血管の拡張と出血を認めた．

　A 58-year-old woman without symptoms underwent upper gastrointestinal endoscopic examination as a routine check-up. It disclosed a polypoid lesion which had gentle marginal slope and was 2～3mm high in the mid-thoracic esophagus (about29～32cm from the incisors). Contraction rings of the esophagus in the vicinity of the polypoid lesion disappeared by pneumatic withdrawal. The second examination was preformed by an oblique-viewing endoscope, the proximal side of the lesion had more gentle marginal slope and was lower than the distal side. There were two longitudinal white-coated erosions on the proximal portion of the lesion, and erythematous area on the distal part. The white coated and erythematous areas were negative for Lugol staining. Radiographic examination with double contrast method showed the lesion as a small granular area which had the same length as a vertebra in the mid-thoracic esophagus. No wall stiffness (poor distensibility) nor irregularity was noted on a profile view of the lesion. Histologic examination of the surgically resected specimen disclosed that the lesion, 19×7mm in size, was well differentiated squamous cell carcinoma limited to the mucosal membrane (invasive depth: ep) which had the thickness of 0.1～0.15mm (macroscopic type: 0-Ⅱa). There were loose fibrosis and lymphoid follicles formation with an enlarged germinal center in the lamina propria mucosae. In addition, dilated blood vessels with hemorrhage were seen in the submucosa beneath the lesion.