Ⅱb病変と近傍非癌粘膜との相異点について―X線診断の立場から

The Difference between Ⅱb Lesion and Neighboring Noncancerous Mucosa from the Radiological Standpoint

　1971年4月第13回日本内視鏡学会総会で初めてⅡbについて臨床的立場でシンポジウムが行われた．打ち合わせで各施設から多くの症例が提示されたが，Ⅱbの定義を実際各症例にあてはめてみると，いろいろな問題が出てきた．これをある程度整理するために，この定義に補則が付けられた．詳細は省くが，結局これらを典型Ⅱb，類似Ⅱb，随伴Ⅱbに分けて検討することになった．著者らは随伴Ⅱbあるいは類似Ⅱbの摘出標本レントゲノグラム（以下“摘出標本R-G”と略す）を用いて，X線像，特にareaの形態，溝による粘膜模様の変化についてretrospectiveに分析して報告した．

　われわれはこのとき得られた成績をもとに，今日まで単独Ⅱbを術前に発見するよう努めてきた．当初は小彎上にあるものだけがcontourの異常だけを手掛かりに発見された．その後，熊倉らによるX線装置の改良やバリウムの改善によって，微細粘膜模様の描写能は著しく向上し，正面像によってかなり微細な模様まで描写されるようになってきた．白壁はシンポジウム後に行われた座談会で将来2cmぐらいのⅡbは診断可能になるだろうと述べているが，われわれの教室においても次第にこれに近いⅡb症例が発見されてきている．

　Roentgenographic findings of the resected specimen of type Ⅱb early gastric cancer were classified into three patterns. Several cases detected through x-ray examination on the basis of the classification were demonstrated. The configuration of the area, the mucosal pattern and the distensibility of the wall on double contrast picture of Ⅱb were discussed and some problems remained unsettled were mentioned. Four cases (five lesions) of typical Ⅱb or nearly Ⅱb-like lesions were selected out of cases of three patterns for our research purpose.

　1) Ⅱb lesions detected before operation are as follows: two lesions 20, 10 mm in diameter, two lesions 10, 5 mm in diameter, one lesion less than 5 mm in diameter.

　2) A lesion less than 5 mm in diameter is situated on the lesser curvature and diagnosed by abnormal flexibility and contour. Two lesions are diagnosed by the finding in en faces but the lesions already have a slight factor of Ⅱa or Ⅱc.

　3) The differences of mucosal pattern between the lesion and its neighbors are not recognized in three lesions, but recognized slightly in two other lesions.

　4) Three lesions which show no any change in mucosal pattern on ROG of fixed specimens are diagnosed before operation by means of double contrast method by which the wall is distended.

　5) It is difficult to distinguish the Ⅱb lesions from surrounding normal mucosa and localized small gastritis-mucosa and the ulcer scar near the lesser curvature is often likely to be seen as Ⅱb lesion.

　6) Less false-positive outcome and more exact endoscopic biopsy have come out as matters to be solved hereafter.