再発を来したCrohn病関連小腸癌の1例

Recurrent Small Bowel Adenocarcinoma Associated with Crohn's Disease, Report of a Case

要旨　患者は40歳代，男性．主訴は腹痛・腹部膨満感．20年以上の経過が推測される小腸大腸型Crohn病患者で，4年前に小腸癌2か所と痔瘻癌に対し手術が施行されていた．再燃時の寛解導入療法効果判定目的での経口的ダブルバルーン小腸内視鏡検査で，回腸に潰瘍と多発小結節隆起を伴う狭窄を認めた．生検にて粘液癌との診断を得たため，小腸部分切除・回盲部切除術が施行された．切除標本の病理組織学的所見では前回吻合部の肛門側に回腸～回腸瘻が形成され，その裂溝潰瘍部に粘液産生豊富な中分化～低分化型腺癌がびまん性に浸潤し，周囲粘膜面にはdysplasiaを伴っていた．本邦のCrohn病小腸癌合併例の文献的検討やサーベイランスに関する考察などとともに報告する．

　We present the case of a man in his 40s with recurrent SBA（small bowel adenocarcinoma）associated with CD（Crohn's disease）. The patient had suffered from ileocolonic CD for more than 20 years. Four years previously, he had undergone partial small bowel resection to remove two SBA lesions and abdominoperineal resection of the rectum for anal canal adenocarcinoma. Oral double-balloon enteroscopy to assess the efficacy of remission induction therapy after relapse showed a stricture with nodular lesions and ulcers in the ileum. Biopsy was performed and histological examination revealed mucinous adenocarcinoma. Therefore, the patient underwent partial small bowel and ileocecal resection. Histological examination of the resected specimen showed an ileoileal fistula at the anal side of the previous anastomosis and growth of adenocarcinoma（moderate to poorly differentiated）coupled with surrounding dysplasia in the fissuring ulcer. Here we present a report of this case along with a literature review of reported Japanese cases of SBA associated with CD, and discuss the requirements for a surveillance program.