炎症性腸疾患の画像所見と鑑別診断—びまん性炎症

Endoscopic Features and Differential Diagnosis of Diffuse Colitis

要旨●炎症性腸疾患の鑑別診断で留意すべき，びまん性炎症を呈する代表疾患を概説した．炎症性腸疾患，特に潰瘍性大腸炎を疑う症例では，びまん性腸炎の鑑別診断が重要となる．びまん性炎症は疾患特異的所見ではなく，さまざまな病因により多彩な粘膜所見が領域性に拡がる．急性炎症では感染性腸炎や薬剤性腸炎が主な鑑別となる．慢性炎症では，潰瘍性大腸炎を中心に，MEFV遺伝子関連腸炎，diverticular colitis，AAアミロイドーシスなども念頭に置く．特に慢性経過の症例では，潰瘍性大腸炎に非典型的な所見を丁寧に拾い上げ，経時的に診断することが肝要である．

　In this study, we reviewed endoscopic features of common diseases that involve diffuse colitis. Various forms of colitis, especially ulcerative colitis, cause diffuse inflammation. Diffuse colitis is not a disease-specific finding. Moreover, inflammation is known to be associated with various mucosal changes. In acute presentation of diffuse colitis, infectious enteritis and drug-induced enteritis are the main differential diagnoses. In chronic presentation of diffuse colitis, in addition to ulcerative colitis, MEFV（Mediterranean fever）gene-related enterocolitis, diverticular colitis, AA amyloidosis, and other diseases should be considered. To diagnose diffuse colitis, colonoscopy should be carefully performed. Atypical features of ulcerative colitis can also be identified through colonoscopy.