[Transitional cell carcinoma of urachus: a case report].

We report a case of transitional cell carcinoma of urachus in a 72-year-old man. At follow up cystoscopy for past history of bladder cancer, we found a papillary tumor in the right orifice that came out to the bladder cavity intermittently. Although there was no cancerous lesion on the surface of the bladder mucosa, a submucosal eminence at the dome of bladder was observed. Sagittal magnetic resonance imaging (MRI) revealed an extravesical tumor (2 cm) at the position of urachus. Under the diagnosis of right ureteral cancer and urachal cancer, we performed right distal ureterectomy, ureteral reimplantation and total resection of urachus. Pathological examination revealed transitional cell carcinoma in the urachus and right ureter. The urachal cavity was isolated completely from the bladder cavity. Tumor infiltrated to the muscularis of the bladder dome from the urachal cavity, but there was no cancerous lesion on the surface of the bladder mucosa. Therefore, our diagnosis was urachal transitional cell carcinoma and right ureteral carcinoma.