小腸腫瘍に対する内視鏡診断の現況

Present Status of Enteroscopy for the Diagnosis of Small Intestina Tumors

　小腸の腫瘍は，良悪性を問わず発生頻度は高くない．しかもその臨床症状は腹痛，腹部膨満感，悪心，嘔吐，貧血，腫瘤触知などと多彩ではあるものの，早期診断の糸口となる特徴的な症状は乏しく，大量の消化管出血やイレウスなどの重篤な症状に陥って，緊急手術や試験開腹術が行われることもまれではない．過去の文献を渉猟しても，小腸腫瘍に対する内視鏡診断に関する報告例は少ない．

　本誌でも過去に3回にわたって，小腸疾患に関する特集が企画された．特に小腸の内視鏡検査法も一応軌道に乗った1976年の企画（第11巻2号：“小腸疾患の現況”）より5年の歳月がたったが，果たして最近の5年間で小腸疾患，殊に腫瘍に対する内視鏡検査法はどの程度の進歩を遂げたものか，興味は尽きない．本稿では小腸腫瘍に対する小腸内視鏡検査法の歴史的背景についても触れながら，併せて今後の問題点についても述べてみたい．なお，本稿における“内視鏡診断の現況”は上記著者らが症例を持ち寄り，討論を加えたものであり，殊に鑑別診断学的な立場からの解析を試みたものである．

　Enteroscopy is a difficult examination compared with upper GI endoscopy or colonoscopy, and the incidence of small intestinal tumors is extremely low in Japan. How many hospitals examine the lesions of the small intestine with enteroscopy?

　Up to date, enteroscopy has been developed along three main line; (1) push type scope, (2) rope-way type scope, and (3) sonde type scope. Using these three types of enteroscope, 19 lesions were examined during the last 11 years. They consisted of three cancers, five malignant lymphomas, one leiomyosarcoma, five leiomyomas, one hemangiopericytoma and five Peutz-Jeghers' type polyps. Endoscopic appearances of the tumors were classified into three groups; Type I is a sessile tumor, type II is a semi-pedunculated or pedunculated tumor and type III is a large tumor with central depression. Type III were classified furthermore into two subgroup, i.e., tumors partially encirculating (type IIIa) and completely encirculating the bowel (type IIIb). Malignant tumors showed various appearance from type II to type IIIb but benign tumors never showed type IIIb. All malignant tumors and some of benign tumors were over 4cm in size, which suggests the difficulty of the differentiation of the malignant tumors from the benign large tumors of the small intestine.