内視鏡的に遡及的検討が可能であった潰瘍性大腸炎合併大腸粘膜内腫瘍の1例

Retrospective Review of Endoscopic Findings of Colitis-associated Intramucosal Neoplastic Lesion : Report of a Case

要旨　潰瘍性大腸炎（UC）発症19年目に診断された，S状結腸のhigh grade dysplasia発生部位の内視鏡画像を遡及検討し，診断までの5年間の画像において平坦な発赤領域を指摘できた．慢性炎症による所見の修飾や，組織学的な確認はなされていないため断定はできないが，初期病変である可能性が強く示唆された．平坦dysplasiaの一部には，本症例のように比較的長く粘膜内病変として留まる病変が存在すること，炎症粘膜においても周囲の性状と異なった発赤領域として認識できる可能性があると考えられた．UC合併腫瘍の発生・進展過程の推定や，サーベイランスにおける関心領域を考えるうえで示唆に富む症例と考え，報告する．

　We retrospectively reviewed the endoscopic findings of colitis-associated high-grade dysplasia arising from a patient with a long-standing left-sided UC（ulcerative colitis）. The lesion appeared as a reddish area 5 years before it was diagnosed. It appeared to be an early lesion ; however, it was difficult to conclude because of the presence of inflammation in the surrounding area and the lack of histological confirmation. It is possible that some flat dysplasia remained as an intramucosal lesion for a relatively long period of time and was identified as a reddish area. The development of UC-associated carcinoma/dysplasia and the efficiency of surveillance colonoscopy are also discussed in this case report.