多発胃癌―病理学的立場から

Multiple Gastric Cancer from the Pathological Viewpoint

要旨　1986年から1991年の6年間に外科的に切除された胃癌症例1,159例のうち，胃癌の多発を266例(23.0％)に認めた．肉眼的に病変を同定できた例に限ると203例(17.5％)であった．多発例の平均年齢は単発の症例に対して有意に高く，男性に多い傾向がみられた．肉眼的に2つの癌を認めた130例においては粘膜内癌同士(31.5％)，あるいは進行癌と粘膜内癌の組み合わせが多く(30.8％)，進行癌同士の組み合わせはまれ(1.5％)であった．組織型の組み合わせでは，副癌巣は高分化型腺癌が多かった．術前には副癌巣は61例で見逃されていた．肉眼的に所見を認めず組織学的に副癌巣を認めた症例が1,159例中66例(5.7％)みられた．高分化型腺癌の多発する胃の背景粘膜には不規則な枝分かれ，拡張を示す腸上皮化生巣が認められた．胃癌の多発の頻度は高く，X線診断医，内視鏡医，病理医とも副癌巣を見つける努力が必要である．組織学的な副癌巣の存在は内視鏡的治療後の経過観察の必要性を示している．

　Simultaneous multiple gastric cancer was found in 266 (23.0%) of 1,159 resected stomach during the period between 1986 and 1991. Macroscopic multiple gastric cancer was seen in 203 (17.5%) stomachs. Multiple gastric cancer was more common in older patients than single one, and was significantly more common in males than in females. The depth of invasion varied among 130 cases with macroscopically detectable double cancer: 41 cases with both intramucosal lesions, 40 cases with an advanced and a intramucosal lesion. On the other hand, cases with both advanced lesions were rare (2 cases). Histological examination of the accessory lesions disclosed that most of them were well differentiated adenocarcinoma. Sixty one cases with accessory lesions were not detected preoperatively. In 1,159 cases with gastric cancer, there were 66 cases with multiple cancer whose second and/or third accessory lesions were not detected macroscopically, but were found only by histological examination. The background gastric mucosa of multiple well differentiated adenocarcinoma accompanied intestinal metaplasia with irregular branch and dilatation. As conclusions, 1) radiologists, endoscopists and pathologists should make more effort to find accessory cancerous lesions because of high incidence of multiple gastric cancer, 2) longterm follow-up for the post endoscopic treatment of gastric cancer is strictly recommended.