非定型大腸Crohn病―5例の呈示とその診断における問題点

Clinical and Pathological Study on Atypical Cases with Crohn's Disease of the Large Intestine

要旨　過去8年7か月間に福岡大学筑紫病院で診断された大腸Crohn病の中で，X線・内視鏡上，アフタ様病変のみから成る例を除き，縦走潰瘍・敷石像を認めない例，潰瘍性大腸炎との鑑別が困難であった例を非典型例とし，その頻度，診断上の問題点を明らかにした．当科の非定型例は3例で全Crohn病患者，大腸Crohn病患者の中に占める割合は，それぞれ1.6％（3/187例），15％（3/20例）であった．更に福岡大学第1内科の非定型例2例を加え計5例を詳細に呈示し検討した．非典型例の臨床的特徴は発症が比較的急激で，5例中4例が下痢・血便を初発症状としており，5例中4例が直腸から連続して病変を認めたことであった．上記所見に加え，再検討により内視鏡上，部分的に介在正常粘膜を伴うアフタ様病変（4/5例）およびX線上縦走潰瘍瘢痕（1/5例）の見落としが明らかになり，病理学的には，手術標本の切り出し不足（2/5例）が，確定診断を迷わせた主な診断上の問題点と思われた．今回の検討に，欧米で報告されている“indeterminate colitis”に重点を置いて文献的考察を加えると，病理材料の検索不足により“indeterminate colitis”に当てはまる例は，十分起こりうることが考えられた．

　Five Cases with large intestinal Crohn's disease which presented atypical features were studied retrospectively.

　We defined the criteria of atypical case radiologically, endoscopically and pathologically as follows: 1) no cobblestone like-appearance, 2) no longitudinal ulcers, and/or 3) diagnostic difficulty to exclude ulcerative colitis. With the exception of cases with solely aphthoid lesions, three atypical cases (15%) were identified out of twenty patients with large intestinal Crohn's disease diagnosed in Fukuoka University, Chikushi Hospital. Two additional atypical cases were selected from the patients who were diagnosed in Fukuoka University, the first department of internal medicine.

　All available clinical examinations and pathological specimens were analyzed and summarized as follows: 1) The clinical course of all five cases was acute onset and the initial symptoms of four cases were both diarrhea and hematochezia. 2) Four cases had continuous lesions from the rectum. 3) By careful reassessment of the colonoscopic and Barium enama pictures, the following two findings might have had diagnostic values. i) The scattered aphthoid ulcers and narrow normal mucosa between them in the colonoscopic films of four cases. ii) The overlooked longitudinal ulcer scars in the x-ray film of one case. 4) Two cases were misdiagnosed with ulcerative colitis by the histopathological findings of twelve and ten sections respectively obtained from the surgically resected specimens. They were re-diagnosed with Crohn's disease by the additional sections of the specimens. The report (Price, 1978) on so-called“Indeterminate colitis”was made by the pathological investigation of eleven sections on the average, which were the same number of the sections as we investigated on our misdiagnosed two cases. These facts suggest that previously reported indeterminate colitis might have included such poorly evaluated cases.

　The careful clinical and pathological evaluation could have reduced the indeterminate cases of inflammatory colonic disease.