微小未分化型胃癌の内視鏡的切除の成績―大きさからみた適応

Indication for Endoscopic Resection for Undifferentiated Type of Minute Gastric Carcinomas from the Aspect of Their Size

要旨　外科的切除が可能で内視鏡的切除（ER）された未分化型胃癌9例9病変を対象とし，その成績と大きさについて臨床診断の実態を述べ，微小未分化型胃癌のERの問題点について報告した．ERした，ひだ集中のない1cm以下の陥凹型86病変のうち未分化型癌は10.5％（9/86）で，微小癌は4.7％（4/86）であった．肉眼型はすべてⅡC型，生検で未分化型癌と診断された．残胃小彎の1病変を除くと胃体中部より口側の病変はなかった．深達度は8病変がm，1病変がsmであった．8病変が一括切除，1病変が分割切除で，lyとvはすべて（一）であった．経過観察で遺残再発例はない．ER前のX線および内視鏡検査での大きさと切除標本上での癌の大きさを比較した．内視鏡でほぼ正確に診断され，誤差は最大2mmまでで，形態診断と大きく違う例はなかった．切除標本は癌の2倍程度の大きさが得られたが，小さい切除や分割切除の例がみられ，切除標本全体の大きさが問題と考えられた．以上から，癌の組織学的拡がりと切除できる標本の大きさからみて，5mm以下と臨床診断した微小癌であれば，未分化型癌におけるERの適応としてよいと考えられた．

　Endoscopic resection (ER) for undifferentiated type carcinomas was considered more dangerous than resection of the differentiated type, because they often had scirrhous invasion even though they are small in size. Nine cases of undifferentiated type of early gastric carcinomas measuring 1 cm or less in size were performed in our department using endoscopic resection. The size of the cancer was diagnosed almost correctly by x-ray and endoscopy before ER but some cases were misdiagnosed because of intramucosal invasion without accompanying depressive changes. Such invasion characterized an undifferentiated carcinoma limited in size to within 2 mm from the margin of its depression. Because of this phenomenon, at the time of ER, it is necessary to resect specimens at least 4 mm larger in size those of carcinomas. We concluded that minute carcinomas of undifferentiated type and less than 5 mm in size might be resected safely if the above mentioned conditions were fulfilled.