注腸X線造影検査による遡及が可能であった潰瘍性大腸炎に発生したcolitic cancerの1例

Ulcerative Colitis-Associated Cancer Retrospectively Investigated using X-ray Examination, Report of a Case

要旨　患者は34歳，男性．31歳時に全大腸炎型の潰瘍性大腸炎と診断され，原発性硬化性胆管炎を合併していた．診断時，S状結腸狭窄を伴っていたため，内視鏡検査に加え注腸X線造影検査も行ったが明らかな腫瘍性病変は指摘できなかった．慢性持続型の経過を呈し，ステロイド薬抵抗性であったため診断6か月後からインフリキシマブ投与を開始し，以後維持投与を継続した．診断から3年後の2013年5月に施行した大腸内視鏡検査で上行結腸に40mm大の隆起性病変が発見された．生検で中分化型腺癌と診断され，手術を施行したところ，漿膜下層まで浸潤する進行癌（pStage II）であった．発癌危険因子を有する潰瘍性大腸炎症例に，短期間に進展したと考えられる進行大腸癌が発生した症例を経験したので，遡及可能であった画像の検討を含めて報告する．

　A 34-year-old man with UC（ulcerative colitis）developed adenocarcinoma 3 years after diagnosis. He was diagnosed with UC（total colitis type）complicated by primary sclerosing cholangitis at 31-years old, and was followed up in our hospital. At the time of diagnosis he had undergone endoscopy because his condition was associated with an S-colon stenosis. On both endoscopy as well as X-ray examinations, no neoplastic lesions were evident. Infliximab administration was started 6 months after diagnosis because of chronic persistent type symptoms that were steroid-resistant, and he was continued on infliximab maintenance dose thereafter. Three years after the diagnosis of UC on May 2013, a colonoscopy revealed a 40-mm elevated lesion in the ascending colon. The lesion was diagnosed as a moderately differentiated adenocarcinoma on biopsy, and surgery confirmed an advanced cancer with subserosal invasion（pStage II）. We report a patient with UC who developed advanced colorectal cancer and consider patients with carcinogenic risk factors together with a retrospective analysis of his imaging.