潰瘍性大腸炎の経過中に狭窄および瘻孔を形成しCrohn病を併発した1症例

Ulcerative Colitis Causing Stenosis and Fistulation Complicated by Crohn's Disease during the Course

要旨　患者は35歳，女性．主訴は発熱，下痢．1976年3月より潰瘍性大腸炎の診断で薬物療法を受けていた．1987年6月発熱，頻回の下痢にて入院．血沈の充進，CRP強陽性，α₂-グロブリンの増加をみた．X線検査でS状結腸から下行結腸の一部に管腔の著明な狭小化を認め，第58病日のX線検査で狭窄部に瘻孔形成をみた．ED投与で瘻孔は閉鎖したが，狭窄は改善せず，下行結腸から上部直腸切除，下部直腸粘膜抜去，下行結腸肛門吻合術を施行した．切除標本では狭窄部に長さ3cmの縦走潰瘍を認め，その粘膜下に膿瘍を認めた．組織学的には口側は粘膜の萎縮，粘膜筋板の著明な肥厚，Paneth細胞の存在など潰瘍性大腸炎の所見があり，その他の部位や所属リンパ節には非乾酪性肉芽腫，膿瘍の中心部には裂溝を認めた．以上より本例は潰瘍性大腸炎の経過中にCrohn病が併発し，狭窄，瘻孔を形成したものと考えられた．

　The patient is a 35-year-old woman complaining of fever and diarrhea. Since March 1976 when ulcerative colitis was diagnosed, she had been receiving drug therapy. From May 1987 she developed fever and increased frequency of defecation. Findings on admission on June 24 were as follows: elevated ESR, CRP-strong positive, increased α₂-globulin (Table 1).

　Barium enema study revealed a remarkable luminal narrowing involving the sigmoid colon and a part of the descending colon (Fig. 2a) and a fistulation at the stenosed region (on day 58) (Fig. 2b). Oral elemental diet was effective in healing the fistula, but not for the stenosis (Fig. 2c), thus leading to the resection of the descending colon, sigmoid colon and upper rectum as well as the removal of the lower rectal mucosa and descending colo-procto-anastomosis. Examination of the resected specimen revealed a 3cm longitudinal ulcer at the stenosed region and submucosal abscess (Fig. 5a～c).

　Histological changes characteristic to ulcerative colitis, i.e., mucosal atrophy, remarkable hypertrophy of the muscularis mucosae and presence of Paneth cells, were noted orally, compared with those characteristic to Crohn's disease, i.e., fissures at the central portion of the abscess and non-caseating granuloma in the intestinal canal and attached lymph nodes (Fig. 6a～d). The above findings suggested that the current case developed Crohn's disease during the course of ulcerative colitis, leading to a stenosis and fistulation.