Renal cell carcinoma (RCC) accounts for more than 90% of cases of malignant kidney tumors and represents 2-3% of all malignancies worldwide. Clear cell renal cell carcinoma (ccRCC), the most common type of RCC, comprising 70–80% of cases. RCC most commonly metastasizes to the lungs, bones, lymph nodes, liver, adrenal glands, and brain. Synchronous metastasis of RCC to the ipsilateral ureter represents an extremely rare event. Ureteral metastasis is a significant diagnostic challenge, since it is quite difficult to determine whether it has metastatic origin (RCC) or it is a primary urothelial tumor. Moreover, due to the rarity of disease, treatment strategy is not well established.
We present a rare case of patient with the RCC of a single left kidney and metachronous metastasis to the ipsilateral ureter that was initially assumed to be primary urothelial carcinoma. The robotic-assisted left-side partial nephrectomy with a segmental resection of left lower ureter and Boari reconstruction was performed.
This case of successful treatment with robotic-assisted approach shows a great organ-sparing potential of robotic surgery in the treatment of complex oncological patients for whom it is extremely important to preserve the maximum volume of functioning renal tissue, particularly in those with a metastatic RCC of a single kidney.

Keywords: metastasis of RCC, ureteral tumor, renal cancer, renal cell carcinoma