胃癌EMR後の異時性多発癌―臨床病理学的検討

Multiple Gastric Cancer after EMR for Early Gastric Cancer : Clinicopathological Study

要旨　1993～2005年に当院で施行されたEMR1,785例中，経過観察中に発見され治療された，異時性多発癌43例111病変について検討した．二重癌27例，三重癌11例，四重癌4例，五重癌1例であった．発生時期は二重癌ではEMR後5年以内に81％で次の病変が発見されていた．三重，四・五重癌ではすべての病変が前の病変から6年以内に発見されていた．組織型は高分化型同士の組み合わせが，それぞれ67％，82％，80％にみられたが，高分化型と中分化，未分化型の組み合わせが18～33％にみられた．刷子縁陽性率は二重癌より，三重，四・五重癌の高分化型腺癌のみの症例に高くみられた．経過観察中に最終的に胃切除が施行された症例が5例あった．5例中3例は3～4cm大のIIa型であり，範囲診断が不明瞭であった．これらの症例は組織学的に高～中分化型腺癌で一部に未分化成分を持ち，免疫組織学的には胃型形質を持った早期胃癌であった．

　We studied about 43 EMR cases including 111 lesions of multiple gastric cancer. We encountered 1,785 EMR cases between 1993 and 2005. Cancer occurred twice in 27 cases, 3 times in 11 cases, 4 times in 4 cases and 5 times in 1 case. We were able to find 2nd cancer within 5 years after first EMR in 81％ of cases. Triple and more cancers were found within 6 years after the previous cancer. In 67％, 82％ and 80％ of the lesions the histological pattern was that of well differentiated adenocarcinoma. Multiple histological type lesions were found in 18～33％. Some lesions were well differentiated adenocarcinoma and other lesions were moderate to poorly differentiated adenocarcinomas. We found blush border in cases of 3, 4, and 5 times cancer. 5 cases were finally operated on after follow up EMR. All the operated cases showed the histology of either well-to moderately differentiated adenocarcinoma or partly poorly differentiated adenocarcinoma. Using immunohistochemical study, the cases had gastric type mucin.