多発大腸癌を併発した潰瘍性大腸炎の1例―本邦報告例の集計を含めて

Ulcerative Colitis Complicated with Multiple Colorectal Cancers Developing over a Short Term, Report of a Case and Review of the Literature

要旨　患者は43歳の男性．粘血便を主訴に28歳で発症．全大腸炎型，慢性持続型の潰瘍性大腸炎として，13年間経過観察を行っていた．1993年12月の内視鏡検査で，上部直腸に大小不同の扁平隆起の集簇した全周性病変を認め，また，直腸S状部に結節状隆起を認めた．生検でいずれも癌を認めたため，潰瘍性大腸炎に併発した多発癌と診断し，大腸全摘術，回腸直腸吻合術を施行した．病理組織学的に，上部直腸病変は深達度smの高分化腺癌と深達度sm，mp，seの粘液癌が混在しており，直腸S状部病変は深達度mの高分化腺癌であった．dysplasiaも存在した．1年4か月の短期間に，進行癌を含む多発癌を併発した潰瘍性大腸炎の症例である．

　A 43-year-old man with ulcerative colitis had been followed up, since 1981, for 13 years. Colonoscopy disclosed two lesions on the rectum (Ra) and the rectosigmoid colon (Rs) in 1993, only one year and four months after the previous examination. Barium enema (Fig. 1) and colonoscopy (Fig. 2) showed a slightly irregular elevated lesion on the Ra and a nodular protruded lesion on the Rs. Biopsy specimen revealed both lesions were cancers, so proctocolectomy was performed. Pathological examination of the resected specimens (Fig. 4) showed that the slightly elevated lesion on the Ra consisted of a well differentiated adenocarcinoma invading the submucosa and a mucinous carcinoma invading the serosa. It also showed that the nodular protruded lesion on the Rs consisted of well differentiated adenocarcinoma invading the mucosa. Surrounding these cancers was low or high grade dysplasia. Our case was the 42nd case of ulcerative colitis complicated with multiple colorectal cancers in Japan. Cancers developing from ulcerative colitis are suspected to grow rapidly compared with the growth rate of ordinary colon cancers.