大腸腫瘍の内視鏡治療後サーベイランス：炎症性腸疾患を背景としたdysplasia/癌

Post-endoscopic Resection of Ulcerative Colitis-associated Neoplasia

要旨●潰瘍性大腸炎関連腫瘍に対する内視鏡的切除は現状の本邦のガイドラインでは適応外で，その適応の判断には慎重さを要する．可視的病変周辺のinvisible flat dysplasiaによる範囲診断困難や，事前の生検診断より切除標本の最終病理診断のほうが悪性度が悪化する可能性がある潰瘍性大腸炎関連腫瘍の病理学的特徴による質的診断の困難性を理解する必要がある．このため切除標本の根治度判定を含めた病理診断は非常に重要で，切除後も遺残再発や異時性再発のリスクがあるため，フォローアップのサーベイランス内視鏡検査の励行も大切である．

　The recent Japan Gastroenterological Endoscopy Society guidelines for colorectal endoscopic submucosal dissection/endoscopic mucosal resection did not include UC（ulcerative colitis）-associated neoplasia as an ER（endoscopic resection）indication. Therefore, ER indication for UC-associated neoplasia should be considered carefully. Pathological diagnosis is crucial to confirm complete or incomplete resection of the resected specimen and decide further strategies for clinical management. Pathological diagnosis with biopsy specimens before ER is challenging due to the invisible flat dysplasia around the visible neoplastic lesion or pathological feature in which the grade of the atypia tends to increase in the deeper layers of the glands in the colonic mucosa. Additionally, surveillance colonoscopy should be performed after ER because patients are at high risk for local and metachronous recurrence.