腎結石に対する腎摘除術後に発生した残存尿管腫瘍

Ureteral stump tumor after nephrectomy for renal stone：A case report

　症例は63歳，男性。無症候性肉眼的血尿を主訴に受診した。23年前に腎結石にて右腎摘除術を施行されている。腹部CTと逆行性尿管造影の所見から右残存尿管腫瘍の診断のもと，右尿管摘除術を施行した。病理診断は尿路上皮癌，G2，pT1であった。術後3年経過しているが，再発はみられていない。良性腎疾患に対する腎摘除後の残存尿管腫瘍は比較的稀な疾患であり，調べ得た限り本邦22例目であった。腎摘除の既往を持つ患者の血尿精査においては，残存尿管腫瘍を念頭に置くことが重要と考える。

　A 63-year-old man was referred to our hospital with the complaint of asymptomatic macroscopic hematuria. He had undergone right simple nephrectomy for renal stone and hydronephrosis caused by ureteral stone. Computed tomography（CT）and retrograde pyelography demonstrated a ureteral stump tumor and resection of the residual ureter was performed. The histological examination revealed grade 2 urothelial carcinoma without muscle invasion（pT1）and adjuvant chemotherapy was not performed. No remarkable recurrence or metastasis has been detected for 3 years after the operation. Ureteral stump tumor occurring after simple nephrectomy for benign kidney disease is relatively rare,however the morbidity rate is higher than common ureteral tumors. Owing post-operative observation after simple nephrectomy especially for infection or stone disease,long-term followup of ureteral stump should be considered.