Crohn病長期経過で発生したStage IV直腸肛門管癌の1例

Diagnosis of Stage IV Anorectal Cancer in a Patient with a Long History of Crohn's Disease：A Case Report

要旨●患者は60歳代，女性．約40年前に発症したCrohn病で，3回の腸管切除歴がある．回盲部切除後の吻合部狭窄で定期的にバルーン拡張術が行われていたが，直腸狭窄がみられたため，当科へ紹介され受診となった．直腸〜肛門管にかけて腫瘍性病変がみられ，生検でadenocarcinoma，tub1であった．CTで肺に腫瘍が指摘され，肺転移を伴う直腸肛門管癌と診断された．手術は腹会陰式直腸切断術が行われ，後日，肺部分切除が行われた．組織学的に肺病変は直腸肛門管癌の転移と診断され，最終診断は，T2，N0，M1，Stage IVであった．Crohn病合併大腸癌は，術前診断が難しく，早期発見はさらに困難であり，サーベイランスも大腸内視鏡検査だけでは不十分である．

　A 60s woman with an approximately 40-year history of Crohn's disease, underwent regular balloon dilation to address the anastomotic stricture that developed after ileocecal resection but was referred to our department due to rectal stenosis. Further evaluation（colonoscopy and enhanced CT）revealed a tumor extending from the rectum to the anal canal, and biopsy revealed adenocarcinoma（tub1）. The CT scan identified a metastatic lesion of the lung, and a diagnosis of anorectal canal cancer with pulmonary metastasis was made. The patient underwent abdominoperineal resection, followed by partial lung resection performed at a later date. Histologic examination of the lung tumor confirmed metastasis, and the final diagnosis was stage IV anorectal cancer（T2/N0/M1）. Preoperative diagnosis of colorectal cancer associated with Crohn's disease is challenging, with early detection even more difficult. Colonoscopy alone is insufficient for surveillance of patients with a long history of Crohn's disease.