抄録
症例は66歳男性,左下腹部痛を主訴に近医を受診した.腹部CTで膀胱左側壁から左精嚢外側に広範囲に接する骨盤内腫瘤を認めた.左尿管は腫瘤に巻き込まれ,水腎,水尿管を呈した.精査加療目的で当科を受診した.組織学的診断のためCTガイド下経皮的針生検を施行したところ,悪性所見は認めず,特発性後腹膜線維症と診断された.しかし,悪性腫瘍に続発した二次的な線維化を否定し得なかったため,閉塞した下部尿管を含めた腫瘤の開放生検を施行した.開放生検の術中迅速病理診断は経皮的生検の診断と同様に,リンパ球の巣状浸潤を伴う膠原線維と線維芽細胞の増生のみで,悪性所見を認めなかった.尿管欠損部はBoari flap法により再建した.本症例は骨盤部に限局した腫瘤形成型の後腹膜線維症であり,骨盤内腫瘍の鑑別診断として念頭に置くべきと考えられた.
A 66-year-old man visited his nearby clinic with a complaint of left lower abdominal pain. Abdominal CT scan showed left hydronephrosis due to lower ureteral involvement by infiltrative retroperitoneal mass located outside of the left posterior wall of the bladder and left seminal vesicle. He was referred to our hospital for further examination. Pathological diagnosis of the percutaneous CT-guided biopsy of retroperitoneal mass was fibrosis without any malignant tumor. Because we could not rule out the possibility of the secondary fibrosis accompanied by malignant tumor, we performed surgical resection of the retroperitoneal mass involving left ureter and confirmed that the mass contains no malignant tumor by frozen section analysis. We augmented the defected ureter by Boari flap method. We should be noticed that retroperitoneal fibrosis could be a differential diagnosis of retroperitoneal pelvic mass.
