急性大腸Crohn病が疑われ追跡検査の結果，潰瘍性大腸炎と考えられた1例

Colitis with a Tentative Diagnosis of Acute Crohn's Colitis Which Turned Out Most Likely to Be Ulcerative Colitis by the Follow-up Examinations of the Retained Rectum, Report of a Case

要旨　31歳男性．急性大腸炎でステロイドによる治療が無効であったため全結腸切除を施行した．切除標本では直腸から下行結腸にかけて広範囲に潰瘍性病変があり，この主病巣より口側に非連続的に散在する小潰瘍を認めた．組織学的には主病巣部にはfissuring ulcerを，また，それより口側では散在する小炎症巣を認めた．以上よりunclassified colitisとしたが，Crohn病である可能性が考えられた．手術後2年9カ月に及び残存直腸の追跡検査を行ったが，Crohn病を示す所見は認められず，潰瘍性大腸炎に一致する所見を得た．また，小腸二重造影や回腸の内視鏡検査では異常所見がなかったので，潰瘍性大腸炎であると考えられた．

　The patient was a 31 year-old man with the chief complaint of bloody diarrhea and abdominal pain. Ulcerative colitis was suspected by barium enema and colonoscopy. Because the patient showed no response to the steroid treatment, total colectomy and ileostomy was performed. Proximal end of the rectum was closed (Hartmann's procedure). Examination of the resected specimen showed extensive ulceration in the rectum, sigmoid and the descending colon with small islands of retained mucosa. Proximal to this ulcerated area, for about 30 cm, there were discontinuous scattered small ulcerations with intervening normal looking mucosa. Histologically, in the ulcerated area there were fissuring ulcerations and transmural inflammation, and in the area with discontinuous ulcers there were scattered foci of acute inflammatory change some of which were located at the site of lymphoid follicle. Because of those findings tentative diagnosis of unclassified colitis possibly Crohn's colitis was made.

　Subsequent follow-up study was performed by repeating proctoscopy and biopsy of the residual rectum for two years and nine months. Ileorectal anastomosis was performed about two years after the colectomy. The findings of the follow-up examinations did not show changes of Crohn's disease and were consistent with chronic ulcerative colitis. In addition to this, double contrast barium study of the small intestine and endoscopy of the ileum showed no abnormalities. Because of the results of the follow-up examinations most likely diagnosis turned out to be ulcerative colitis.