胃癌の発生を考えさせる興味ある経過を示したⅡcの1例

A CASE OF EARLY GASTRIC CANCER TYPE Ⅱc SHOWING THE OCCURRENCE AND INTERESTING DEVELOPMENT BY ENDOSCOPICAL RETROSPECTIVE STUDY

はじめに

　胃癌がどのような形で発生し，どのくらいの期間早期胃癌の状態でとどまっているのであろうかということは胃癌の早期発見に携わる者にとって大きな関心事である．胃カメラをはじめ内視鏡検査法の進歩により良好なカラー写真が記録保存できるようになったため胃癌患者の過去の内視鏡所見を探し求め，これと切除胃の組織所見を比較検討して胃癌の進展経過を解析できるようになった．このような研究は一般にretrospective studyと呼ばれている．

　retrospective studyによってこれまでに明らかにされたことは，早期胃癌症例では案外に進行の遅かったものが少なくない^1)2)3)4)ということである．すなわち数年前に遡っても，手術時の形態とほとんど同じ特徴を示すものが経験されたので，多くの胃癌はその早期の時点においては意外にゆっくりと進展するのではないかと考えるようになった．しかしながらこれまで胃癌の成り立ち，あるいは発生を論ずるための資料は極めて少なかったように思われる．著者らはすでに本誌で，隆起型早期胃癌の発生を考えさせる興味ある1例⁵⁾を紹介した．今回は陥凹型早期胃癌の発生を考察する上で貴重な資料と思われる症例を経験したので報告する．

　This is a report of a case of Ⅱc type early gastric cancer, belonging to so-called ulcerating cancer type, which after 5 years became of almost normal mucous membrane as seen by endoscopy. Its process has been retrospectively analyzed by 10 endoscopical findings obtained intermittently during the coarse of the follow-up.

　The case is a 49-year-old male, whose endoscopical finding of the stomach 5 years and 3 months prior to the operation was almost normal. During a couple of years before the operation, endoscopy revealed alternating phases of healing and exacerbation of the benign cycle. Since 1 year and 7 months preceding the surgical intervention, endoscopical findings became suspicious of Ⅱc, and small ulcers within the lesion came and went. In the interim the depression became more and more manifest without any noticiable change of the extent of Ⅱc. Pathological diagnosis at operation was adenocarcinoma (CATⅢ, SAT 3, INF 7) tubulare mucocellulare, sm (LN 0 /15, Ul-Ⅲ).

　The case here described is considered to reveal a phase of veering from the benign to the malignant cycle, and yet it does not necessarily eliminate another point of view that the ulcer within the lesion, only of a secondary nature, is an outcome of Ⅱb.

　The authors' attitude toward the question wher and how the lesion became cancerous is further discussed together with subjects which shall be at issue in the future.