Right-sided型潰瘍性大腸炎の1例

Right-Sided Ulcerative Colitis, Report of a Case

要旨　潰瘍性大腸炎は直腸を含めて，びまん性にびらん・潰瘍を形成する慢性炎症でありその典型例のX線・内視鏡診断は容易である．しかし区域性大腸炎や右側結腸炎型の非典型的な病像を呈する場合にはCrohn病や腸結核との鑑別が問題になる．下痢を主訴とする18歳の女性に対する注腸・内視鏡検査で，横行結腸から盲腸にかけての右半結腸にびまん性のびらん，Haustraの消失と腸管の短縮・狭小化がみられた．経過観察中に横行結腸に小さな偽憩室も形成された．右半結腸切除術により本例はright-sided型潰瘍性大腸炎と診断されたが，遡及的にX線・内視鏡像を振り返ってみると，病変部が右側結腸に限局していたことを除いて，その炎症所見は潰瘍性大腸炎の所見に合致すると考えられた．

　Ulcerative colitis is characterized by chronic inflammation and diffuse ulcerative changes involving the rectum. Its typical cases are easily diagnosed by x-ray examination and endoscopy, however, it is still difficult to differentiate its atypical type, segmental or rightsised colitis, from Crohn's disease or intestinal tuberculosis.

　An 18-year-old female was admitted to our hospital complaining of diarrhea. Barium enema study and endoscopy (Figs. 1 and 2) showed remarkable inflammation in the right colon; diffuse erosions, loss of haustral pattern, contraction of colon lumen, back wash ileitis, and so on. During the follow up observation, several pseudodiverticula were observed in the transverse colon. However, left colon and rectum proved to be intact by the repeated examinations with magnifying endoscopy and biopsy. Right hemicolectomy was performed after conservative treatment with steroid hormone, salicylazosulfapyridine, antituberculotic drugs, and others for three years and six months. Histologically, nonspecific inflammation with inflammatory cells and crypt abscess was detected in the mucosa and submucosa (Flg. 9), establishing the diagnosis of right-sided ulcerative colitis.