膀胱後部に腫瘤を形成した尿膜管腫瘍の1例

Abstract

症例は14歳女児で, 臍周囲の発赤, 腫脹, 血性滲出を認め, 小児科よりの紹介で来診した.腹部超音波検査で膀胱後壁より突出する辺縁平滑な腫瘤像を認め, 膀胱鏡でも膀胱後壁の腫瘤を認めた.入院後の膀胱, 瘻孔造影では膀胱と尿膜管との交通は認めず膀胱の後部へと尿膜管腫瘍が続いていた.同時に左膀胱尿管の逆流を認め, MRIでは臍部より連続する尿膜管が膀胱後部へ連続しており, 内部の不均一な腫瘤影を認めた.これら所見から膀胱後部に腫瘤を形成した尿膜管腫瘍の診断で, 保存的治療を試みたが無効のため尿膜管切除および左膀胱尿管新吻合術を施行した.膀胱後部の腫瘤は結石を核とする炎症性に肥厚した膀胱子宮窩の組織と判明した.摘出標本は上皮の剥離した炎症細胞浸潤を認める肉芽組織で, 移行上皮成分は認めず, 腫瘍組織も認めなかった.術後経過は良好で, 約1年経過の現在, 腫瘍の再発, 膀胱尿管逆流は認めていない

A 14-year-old girl was admitted to our hospital because of umbilical erythema and discharge. She had had an appendectomy at the age of twelve. Abdominal ultrasonography and cystoscopy revealed a large tumor-like mass at the posterior wall of the bladder. Computed tomography and magnetic resonance imaging revealed urachal sinus. The diagnosis of urachal abscess had been confirmed and conservative treatment had been continued by drainage via umbilicus and the administration of antibiotics. Total excision of the urachus was performed about one month later because the bladder mass was not reduced. Pathological findings revealed an inflammatory thickened wall of the urachus and no evidence of malignancy. We report this rare case of urachal abscess with a large mass in the retrovesical space.