早期食道癌の拾い上げの反省と対策

Reflection upon the Detectability of Early Esophageal Carcinoma at the Initial Radiological Examination

要旨　食道の早期癌をep癌とmm癌だけに限定し，切除材料で，まず単発病変と多発病変に分け，各々の部位と大きさから，X線診断と内視鏡診断とを比較検討した．そして，X線診断の立場から，ep癌とmm癌のX線診断能，診断限界を検討した．単発のep癌16病変，mm癌21病変でみると，初回にX線検査を受けた例では，Ⅰ型とⅡa型(隆起型)の診断は良かった．しかし，Ⅱb型とⅡc型(平坦型と陥凹型)の診断は良くなかった．ep癌はすべて見逃したが，mm癌の中には診断できた例もあった．ep癌とmm癌のX線所見の差は辺縁の異常所見の程度にあることがわかった．以上から，mm癌はX線検査で十分に発見できると思う．部位からみると，Ph-Ceの診断はX線検査でも内視鏡検査でも困難で，いま大きな課題である．

　Early carcinoma of the esophagus is defined as carcinoma which is limited to the submucosa (sm-ca.) without lymph node metastasis, and superficial carcinoma is defined as that which is limited to the submucosa regardless of whether or not there is lymph node metastasis. These two types of carcinoma have the same depth of invasion, but it has been found that this categorization is not completely suitable.

　Considering the fact that there is an unfavorable prognosis for sm-ca., it is desirable that a more clealy delineated definition of sm-ca. (early carcinoma) showld be formulated.

　We propose two types in place of the sm-ca. type. 1) The type limited to the epithelium (ep-ca.), and 2) The type invading the muscularis mucosae (mm-ca.).

　In the last 16 years, forty-three cases with 52 lesions of ep-ca. and mm-ca. have been detected and resected in our hospital. Most of the elevated type of ep-ca. and mm-ca. were detected by the radiological examination. On the other hand, in the depressed type, all cases of the ep-ca. and half of the cases of mm-ca. were overlooked.

　In the ep-ca., a minimum degree of poor distensibility, and iregularity of the margin were visualized on a profile view with slight esophageal distension. These marginal abnormalities were effaced in moderate esophageal distension. However, mmca. types were not effaced by a changing degree of esophageal distension. It was suggested that mm-ca. could be detected in the initial radiographic examination through meticulous interpretation.