潰瘍性大腸炎に大腸癌を合併した2症例

Ulcerative Colitis Complicated with Colorectal Cancers, Report of Two Cases

要旨　1例目は22歳男性．13年前発病，4年前の注腸造影では直腸より下行結腸にかけて腸管の伸展不良，粘膜粗縫がみられた．今回下血頻回のため注腸造影を施行したところ，直腸に陰影欠損を認めた．切除標本では2型腫瘍で，組織学的には深達度a₂の高分化型腺癌であった．この病巣に接してdysplasiaがみられた．2例目は44歳男性．12年前発病，最近，下血持続のため近医受診，直腸に腫瘍を指摘された．注腸検査で大腸は短縮狭小化し，粘膜は粗糙であった．更に直腸に陰影欠損，直腸・S状部に隆起性病変を認めた．切除標本では前者は深達度a₂，後者はsmの分化型腺癌で，更にこれら以外にも，直腸にpm，直腸・S状部にsmの分化型腺癌，S状結腸にpmの低分化腺癌を認めた．病巣周囲にはdysplasiaが存在した．

　〔Case 1〕A 22 year-old man had been diagnosed ulcerative colitis (UC) 13 years previously. X-ray and endoscopic examinations four years before admission revealed left sided colitis. He complained of hematochezia and abdominal pain, and was found to have rectal tumor. Resected specimen showed ulcerated cancer and a whitish plaque-like lesion. Histological examinations disclosed well differentiated adenocacinoma and associated low-grade dysplasia.

　〔Case 2〕A 44 year-old man admitted to the hospital with a complaint of fematochezia. He had been diagnosed as having total colitis 12 years earlier. Radiological and endoscopic examinations revealed rectal tumor and elevated lesions at rectosigmoid. Biopsy specimens disclosed adenocarcinoma, and total proctocolectomy was performed. Resected specimen showed four lesions of well differentiated adenocarcinoma at the rectum and rectosigmoid junction, and one of poorly differentiated adenocarcinoma at the sigmoid colon. Macroscopically, two of the five were flat or finely nodular and escaped clinical detection. These malignancies were surrounded by extensive or patchy lesions of various degree of epithe lial dysplasia.