Crohn病と潰瘍性大腸炎における大腸初期病変の比較

Aphthous Lesions of the Colon : A Comparison between Crohn's Disease and Ulcerative Colitis

要旨　初回診断時アフタのみのCrohn病（A型CD）15例と，診断前にアフタ様病変が確認された潰瘍性大腸炎（E型UC）5例の初回大腸病変および経過を比較した．アフタはリンパ濾胞様小隆起（I型），大型のリンパ濾胞様隆起（II型），発赤を伴う小白点（III型），白苔を伴う小潰瘍（IV型）に大別した．A型CDの主たる病変はI型のみが3例，II型が1例，III型が7例，IV型が4例で，E型UCではII型（3例）ないしIII型（2例）アフタを認めた．A型CD8例は3～108か月（平均29か月）で小腸型（4例），大腸型（1例），ないし小腸・大腸型（3例）Crohn病へと進展した．E型UCでは3～66か月（平均18か月）後に全大腸炎型UC（1例），と遠位型ないし区域性潰瘍性大腸炎（4例）に進展し，後者の3例は全大腸炎型UCへと進展した．以上より，アフタ様病変は潰瘍性大腸炎の初期病変であるが，内視鏡所見はCrohn病とは異なると結論した．

　We compared the initial and subsequent colonoscopic findings of 15 patients with Crohn's disease of aphthous type (A-CD) and 5 patients with early ulcerative colitis (E-UC). Three A-CD patients were affected by type I aphthous lesions (small protrusion with minimal depression), one A-CD patient was affected by type II aphthous lesions (obvious protrusion with minimal depression), seven A-CD patients were affected by type III aphthous lesions (white spot surrounded by reddish mucosa) and four A-CD patients were affected by type IV aphthous lesions (small ulcer). E-UC patients comprised three patients affected by type II aphthous lesions and two patients with type III aphthous lesions. Eight A-CD patients progressed to overt Crohn's disease during periods ranging from 3 to 108 months, and all five E-UC patients progressed to ulcerative colitis during periods ranging from 3 to 66 months. These observations suggest that in both Crohn's disease and in ulcerative colitis, aphthous lesions are precusors of respectively typical colonic involvement, although the colonoscopic features of the precusor differ somewhat between the two diseases.