18歳男性に発生した膀胱移行上皮癌

A case of transitional cell carcinoma of the bladder in a young male：A case report

　18歳，男性。肉眼的血尿を主訴に受診し，精査の磁気共鳴尿管膀胱造影（MR urography）にて膀胱腫瘍を認めた。膀胱鏡にて左尿管口外側に約10mm大の乳頭状腫瘍，他2箇所に娘腫瘍を認めた。生検結果はpapillary urotherial neoplasm of low grade malignancyであり，画像上転移所見を認めなかった。経尿道的膀胱腫瘍切除術施行，病理結果は尿路移行上皮癌，grade 1であった。

　We report a case of transitional cell carcinoma of the bladder in an 18-year-old male whose chief complaint was macrohematuria. Magnetic resonance imaging（MRI）revealed a tumor lesion in the bladder,and cystoscopy showed the main tumor at the upperside of the left ureteral orifice with daughter tumors at other sites all in the bladder. A biopsy of the main tumor was papillary urothelial neoplasm of low malignant potential. Transurethral resection of the bladder tumor was performed and the pathological diagnosis was a grade 1 transitional cell carcinoma of the bladder. No recurrent findings have been observed on cystoscopy following the operation. Bladder tumors that form in the first 2 decades of life are distinctly unusual,and account for just 0.2％ of all urothelial neoplasms. In general,they are solitary,low-grade tumors with good prognosis. However,some show a progressive course,and a strict and long follow-up period is necessary. In young patients with macrohematuria,it is important to take bladder tumors into consideration,and cystoscopic examination should not be hesitated.