Ⅱb型早期胃癌の臨床病理，特にllbの定義の適用条件について

Clinicopathological Aspects of Type Ⅱb Early Carcinoma of the Stomach

要旨　早期胃癌の肉眼分類は癌表面の凹凸をもって類別されている．その表面の凹凸はⅠ型→Ⅱc型へと連続的に変化させうるものであるから，早期胃癌肉眼分類は連続体の分割である．したがって，その分類においてはどの類に属するのか不確実な3つの領域が生ずるのは必然である．その3つの不確実領域Ⅰ～Ⅱa，Ⅱa～Ⅱb，Ⅱb～Ⅱcのうち，Ⅱb近傍の癌の分類適用のみが問題とされるのは，“X線・内視鏡診断法の極限を求めて”という命題が残されているからであろう．不確実領域のものの類別においては，観察方法と人のパターン認識の感性とによって左右される．なぜならば，5つの観察方法，組織標本，固定肉眼標本，新鮮肉眼標本，内視鏡写真，そしてX線写真のそれぞれの所見間のⅡbであるとする一致率は50～60％であるからである．したがって，Ⅱb型とするためには条件づけが必要となる．それは，3つ以上の所見がⅡb型である場合をⅡb型癌とすることであろう．もし，5つの観察方法でⅡbであることとすると，胃のおかれた状態像が問題とされるし，またⅡbとは微小癌においてのみ存在するということになってしまう．

　Applying cancers to the classification of early arcinoma of the stomach, type IIb always becomes a subject of discussion. This is a reason why there is the preoperative diagnosis of type IIb as one of pending propositions into diagnostic theory for early detection of gastric cancer almost established. For discussing on preoperative diagnosis of type IIb, it is necessary to attach a condition to the set of type IIb. Because, type IIc or IIa is sometimes included into the set of cases classified as type IIb.

　Twenty-eight carcinomas were interpreted ns type IIb in over a finding out of five findings studied on cut-surface of histological specimen, resected stomach fixed with formalin, fresh resected stomach, endoscopy, and radiology. Consistent frequency as type IIb among each finding is 50 to 60% in the 28 carcinomas. It may be proposed that type IIb is applied in case that over three out of the five findings show it.

　In 28 carcinomas, 10 were interpreted as type IIb in all the five findings, and measured less than 2cm in largest diameter. Ten carcinomas of type IIb were histologically discovered as one of double cancer. Five carcinomas out of 10 were different from the neighboring gastric mucosa in surface appearance and in color. Generally speaking, the surface is rough and the color is white or reddish in comparison with non-affected mucosa.

　Histologically, seven out of 10 carcinomas were differentiated, and three undifferentiated. The undifferentiated carcinoma horbours princpally in the stomach with well-preserved fundic gland mucosa, meanwhile the differentiated does in the stomach with marked intestinal metaplasia and atrophic fundic gland mucosa.

　The undifferentiated carcinoma which consists histologically of mucocellular and trabecular carcinomas in the mucosa has a tendency to easily erode with peptic affection.