内視鏡的治療を施行した胃I型カルチノイドの1例

Gastric Type I Carcinoid Treated by Endoscopic Submucosal Dissection, Report of a Case

要旨　患者は80歳代，女性．近医にて貧血の精査目的で受診した上部消化管内視鏡検査で，胃体中部小彎に10mm大の立ち上がり明瞭で扁平な隆起性病変を認めた．インジゴカルミン色素撒布観察では，表面に不整な陥凹や潰瘍形成を認めなかった．NBI併用拡大内視鏡観察では，拡張した血管の末梢で細かいnetworkを形成した異常血管を認めた．また，胃体部優位の胃粘膜萎縮を認め，抗胃壁細胞抗体と抗内因子抗体が陽性であった．以上から，I型カルチノイドと診断した．超音波内視鏡検査で，腫瘤は第2層に限局しており，ESDを施行した．クロモグラニンA陽性の腫瘍細胞は，粘膜内に限局して横方向に伸展し，脈管侵襲を認めず，断端陰性であった．非典型的な形態のI型カルチノイドに対して，詳細な内視鏡観察の後にESDを施行した症例を経験したので報告する．

　A woman in her 80s with gastric tumor found at previous institution came to our institution. Gastroscopy revealed a slight elevated lesion with clear margin of 10mm in diameter located in the lesser curvature of the middle-third of the stomach and severe corpus-limited atrophy. Chromoendoscopy detected no irregular depression and ulceration on the lesion. Magnifying endoscopy with NBI revealed fine network of abnormal vessels. The serum anti-parietal cell antibody and anti-intrinsic factor antibody was positive. Endoscopic submucosal dissection was performed for the type I carcinoid with atypical shape. Histological examination showed that Chromogranin A-positive carcinoid cells extended in a horizontal direction limited in the mucosa without lymphatic and vascular invasion, and vertical and horizontal margin were negative.