1)上部消化管

Radiological Diagnosis of Submucosal Tumor in Upper Gastrointestinal Tract

要旨　粘膜下腫瘍（非上皮性腫瘍）のX線診断における基本的な4つの要素について述べた．隆起表面の性状は正常粘膜で覆われ平滑であり，隆起の立ち上がりは山田I型を呈するものでは境界が不鮮明だが大きくなると山田II型やIII型様に境界は鮮明となる．しかし，胃外性発育するものや胃壁外からの圧排ではX線診断が困難であった．bridging foldは粘膜下腫瘍に特徴的ではあるが粘膜下に腫瘍組織が存在すれば他の疾患でも出現することがあるので注意する．隆起が大きくなると頂上に中心陥凹がみられるが陥凹の大きさにより悪性腫瘍との鑑別が必要となる．X線診断の実際にあたっては大きさ，部位，壁外性圧排の有無，硬さの程度をみることも重要であった．さらに，良悪性や上皮性か非上皮性かの判断には中心陥凹やbridging foldの性状に注目する必要があった．

　Basic findings indicative of submucosal tumors of the stomach were discussed from a radiological point of view. On X-ray diagnosis, there were four important features to be observed ; the surface, the margin of the tumor, bridging folds and central depression. The surface of submucosal tumors is usually shown as very smooth because such tumors are covered with normal gastric mucosa. The gradually elevated tumors show obscure margins of radiolucent shadows. Yamada's classification is available for the site of submucosal tumors of the stomach but it is impossible for it to diagnose exogastric tumors. Bridging folds considered as the most characteristic finding of submucosal tumors can be recognized not only in cases of submucosal tumors but also in other diseases. Central depression of the tumors was formed as they developed into bigger tumors and were suspected of being malignant tumors. It was also important to discuss the size, the location and the rigidity of tumors. By combining such radiological findings of submucosal tumors we still have to discuss always whether the tumors are epithelial or non-epithelial and whether they are benign or malignant.

　1) Department of Internal Medicine, Social Health Insurance Medical Center, Tokyo

　2) Department of Radiology, Social Health Insurance Medical Center, Tokyo

　3) Department of Pathology, Social Health Insurance Medical Center, Tokyo