潰瘍性大腸炎に発生した直腸腫瘍の1例

Rectal Tumors in Ulcerative Colitis, Report of a Case

要旨　患者は51歳，女性．18歳で潰瘍性大腸炎と診断されたが，最近20年間は治療を受けていなかった．健診の便潜血反応が陽性のため，前医で下部消化管内視鏡検査が施行された．直腸に隆起性病変を認め，当センターを紹介された．当センターで再検し，隆起性病変（1）に加え，平坦型病変を2病変（病変（2），（3））認めた．生検で病変（1）は潰瘍性大腸炎関連大腸癌，病変（2）はdysplasiaと診断され，腹腔鏡補助下大腸全摘回腸囊肛門吻合術が施行された．病理組織学的には，病変（1）はSM深部浸潤癌，病変（2），（3）はlow to high grade dysplasiaであった．また内視鏡検査で指摘しうる範囲を超えた部位で，HE染色で診断できないp53陽性を示すlow grade dysplasiaを認めた．

　A 51-year-old woman was referred to our hospital for scrunity of a rectal protruded lesion which had been detected by CS（colonoscopy）for positive fecal blood test in another hospital. She was diagnosed as ulcerative colitis when she was 18 years old, but she stopped medication by herself 20 years ago. CS in our hospital revealed two other flat lesions near the rectal protruded lesion.

　Pathological findings of the biopsy specimens revealed adenocarcinoma from protruded lesion and dysplasia from flat lesions. The lesions were diagnosed as UC associated with colon cancer and dysplasia, and laparoscopically assisted ileal j-pouch-Anal Anastomosis was done. Pathological findings of the surgical specimens revealed massively invasive submucosal cancer with low to high grade dysplasia.

　Low grade dysplasias with positive p53 staining were seen out of the lesions which were diagnosed as cancer and dysplasia by CS. These couldn't be diagnosed with only HE staining.