INTESTINE Vol.13 No.3(2-1)


特集名 colitic cancer診断update
題名 2. 診断 (1) 内視鏡診断 -- 通常観察
発刊年月 2009年 05月
著者 岩男 泰 慶應義塾大学包括先進医療センター
【 要旨 】 潰瘍性大腸炎(UC)の長期経過例に大腸癌(UC-associated cancer;UCAC)が高率に合併することが知られている.UCACをサーベイランスし早期診断するためには,臨床的特徴や内視鏡所見を理解しておく必要がある.従来,サーベイランスは寛解期に施行すべきとされているが,自験例の検討では約60%は臨床的活動性のある症例に発見されている.炎症性ポリープや管腔の狭小化など内視鏡的に慢性炎症の持続を示唆する所見は高危険因子である.多発傾向があるが病変の約70%以上,深達度の深いものの90%以上が直腸・S状結腸に発生している.早期肉眼形態のうち隆起型病変として発見されたものが約70%を占めるが,近年,平坦型や陥凹型の発見例も増加している.これらの平坦病変のほとんどが発赤を呈する病変として認識されていた.高危険群を対象とし,粘膜治癒が得られていない部位,とくに直腸・S状結腸を重点的にサーベイランスする必要がある.また,わずかな粘膜模様の変化や周囲と異なる発赤領域に留意し色素内視鏡や拡大観察を含めた詳細な内視鏡観察が重要である.
Theme Update in management of colitic cancer
Title Endoscopic diagnosis of colorectal cancer associated with ulcerative colitis
Author Yasushi Iwao Center for Comprehensive and Advanced Medicine, Keio University School of Medicine
[ Summary ] An increased risk of ulcerative colitis-associated cancer (UCAC) has been reported in patients with long-standing ulcerative colitis. Therefore, cancer surveillance is recommended. Because it is difficult to detect dysplasia occuring in the flat mucosa, current practice guidelines recommend surveillance programs using random biopsy specimens. However, satisfactory results have not been obtained with this technique. It is essential in terms of early detection of UCAC to understand the characteristics of endoscopic findings for those lesions. Clinical features and macroscopic findings, including the mucosal color of 43 cases (71 lesions) UCAC and dysplasia with retrospective follow-up, were analysed. Twenty six out of the 43 (60.5%) were in the clinical active stage and all 71 lesions were surrounded by severe or moderately active inflammation. Fifty three lesions out of 71 (74.6%) were located in the rectum and sigmoid colon. In 53 lesions related to early UCAC and dysplasia, forty two lesions (79%) were of the protruded type, 11 lesions (21%) were of the superficial type including the flat and/or depressed type. Most lesions, especially of the superficial type, were observed to be red. We would like to emphasize that selection of patients in high risk groups and careful examination using chromoendoscopy are essential to detect dysplatic flat or plaque-like elevated lesions which present with faint redness. We hope for the development of new endoscopic techniques, including magnifying endoscopy, to detect flat dysplastic lesions.
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