小腸悪性腫瘍の診断と治療―消化管内分泌細胞腫瘍（カルチノイド腫瘍）

Small Bowel Carcinoids

要旨　小腸カルチノイド腫瘍は，本邦では比較的頻度の低い疾患である．従来，小腸カルチノイド腫瘍の多くは進行した状態で発見されていたが，カプセル内視鏡検査やバルーン内視鏡検査などの小腸内視鏡検査法の普及とともに，最近では早期に発見される症例が増えている．小腸カルチノイド腫瘍の内視鏡的特徴は，色調が黄白色調で表面平滑な粘膜下腫瘍様隆起であるが，他の小腸粘膜下腫瘍との鑑別が困難なことも多いため，各種画像検査所見などにより総合的に判断する必要がある．治療の原則はリンパ節郭清を伴う外科的切除である．転移や異時性多発性病変の早期発見のためには，腹部CT検査や小腸内視鏡検査による術後の定期的なサーベイランスが必要である．

　Small bowel carcinoids are rare in Japan compared to Western countries, and most of these lesions were used to be difficult to be diagnosed before surgical operation. Recently, the prevalence of small bowel carcinoids has progress in endoscopic diagnosis using capsule endoscopy or balloon endoscopy. The endoscopic findings of the typical carcinoids look like submucosal tumors with yellowish color and smooth surface, however, some of the cases are difficult to distinguish between carcinoids and other submucosal tumors such as GIST, etc. In general, the degree of malignant potential of small bowel carcinoids is high compared to gastric or colorectal carcinoids. The metastasis of lymph node or liver has been reported even from small bowel carcinoids which are less than 10mm in size, and the incidence of synchronous tumors is also high. The treatment method of small bowel carcinoids is radical surgery with lymphadenectomy. In the near future, the analysis of clinicopathologic features from many early stage small bowel carcinoids will make it possible to establish the management or surveillance program after treatment.