類似随伴Ⅱb型早期胃癌の1例

A Case of Early Gastric Cancer Diagnosed as Concomitant Ⅱb-like Lesion

　1962年の第4回日本内視鏡学会総会にて早期胃癌の肉眼分類が提案されたが，その時点においては“周辺正常粘膜と同じ高さを示している癌”と定義されたⅡbは，臨床的に術前に診断を下すことのできる可能性はきわめて低く，病理組織学的検索にてはじめて診断が可能の病変と一般的に考えられていた．しかし近年の胃X線診断，内視鏡診断，胃生検などの進歩はめざましく，Ⅱb病変の報告は年を追って増加している．

　1971年の第13回日本内視鏡学会総会においてはⅡbがシンポジウムにとり上げられ，Ⅱb病変が典型Ⅱb，類似Ⅱb，随伴Ⅱbと分けられ，臨床的に術前診断がどの程度まで可能であるかが検討される段階にはいってきた．われわれは術前に類似随伴Ⅱbの診断をしえた早期胃癌の1例を経験したので報告する．

　The patient was a 58-year-old man. There was nothing to contribute in family history, past history, physical examination and laboratory reports. Abnormal finding was detected in gastric mass survey. After close examination of radiograph and endoscopy, he was diagnoed as Ⅱb+Ⅱa+Ⅱc type of early gastric cancer. Gastric biopsy showed positive result. In the resected specimen, the lesion mesured 6.5×10.0 cm. The mucosa of Ⅱb had the mixed appearance of slight protrusion and flatness. In the area of Ⅱb, no remarkable unevenness was observed with surrounding normal mucosa and the area was diagnosed as concomitant Ⅱb-like lesion. It was histologically adenocarcinoma tubulare with m degree invasion as a whole, but with partial slight sm invasion in Ⅱc area. Final diagnosis was early gastric cancer of Ⅱb+Ⅱa+Ⅱc type mainly occupied by Ⅱb-like lesion.

　In this case, x-ray findings of Ⅱb-like lesion were as follows. The lesion could be visualized most clearly in double contrast radiograph. In comparison with the surrounding normal mucosa, Ⅱb-like lesion showed an image of assembly of lower protrusions than that of Ⅱa type early cancer. It looked like an assembly of the round transparent shadows, which were circumscribed by irregular ditches. The width of each ditch was varied. As a whole image of the x-ray finding, the mucosa of Ⅱb-like lesion seemed as if gastric areas were oppressed to flat.