Abstract
Background:
Renal cell carcinoma (RCC) rarely metastasizes to the contralateral ureter. Fewer than 10 such cases have been reported, mostly involving clear cell RCC (CCRCC) with associated hydronephrosis and renal insufficiency. The mechanism may involve retrograde tumor cell implantation via the urine. This report presents a rare case of unilateral CCRCC with synchronous contralateral ureteral metastasis and its treatment.
Case presentation:
A 77-year-old male patient presented with hematuria and right lumbar pain. Computed tomography (CT) imaging revealed a left renal mass and a small right ureteral mass with hydronephrosis and suggested malignancy in both masses. Owing to bilateral involvement and poor general condition, a staged approach was adopted. Laparoscopic partial nephrectomy of the left renal mass yielded clear cell renal cell carcinoma (CCRCC). Subsequent laparoscopic nephroureterectomy for the right ureteral tumor confirmed CCRCC metastasis. The patient recovered well and showed no metastasis at the fourteen-month follow-up.
Conclusion:
This type of metastasis deserves increased attention. However, there is currently no standardized treatment protocol for this rare condition. Our treatment involved firstly management of the renal tumor, followed by the contralateral ureteral tumor so that optimal safety and minimum oncological progression can be achieved.
Introduction
The most common distant metastatic sites of renal cell carcinoma (RCC) are the lung, bone, lymph nodes, liver, adrenal gland and brain (). Ureteral metastasis is relatively rare, especially contralateral ureteral metastasis, which occurs even less frequently in a synchronous manner. Fewer than ten cases of synchronous contralateral ureteral metastasis from RCC have been reported to date (–). Predominantly, these cases involve clear cell renal cell carcinoma (CCRCC), with hydronephrosis and renal insufficiency on the same side as ureteral metastasis. This condition may be associated with a poorer prognosis than metachronous metastasis due to its distinct phenotype (). The mechanism for ureteral metastasis remains unclear. One proposed hypothesis is that tumor cells shed into the urine followed by retrograde implantation into the contralateral ureter (). Here, we report a rare case of unilateral renal clear cell carcinoma with synchronous contralateral ureteral metastasis and our treatment.
Case presentation
A 77-year-old male patient was admitted to our hospital due to hematuria on June 12, 2024, accompanied by mild lumbar soreness on the right and without any lower urinary tract symptoms or systemic symptoms. The patient had a history of hypertension and diabetes, both of which were managed with medication.
On admission, ultrasound examination revealed a solid mass at the upper pole of the left kidney. Urinalysis revealed occult blood (2+) and urine leukocytes (+-). Computed tomography (CT) revealed a 56*53 mm soft tissue mass at the upper pole of the left kidney with uneven density and a suspected malignant tumor (Figures 1A, C). In addition, a small mass, approximately 1 cm in diameter, was also noted near the upper segment of the right ureter, accompanied by right ureteral dilation and hydronephrosis (Figures 1B, D). Computed tomography angiography (CTA) confirmed the left renal mass, showing uneven density (plain scan CT value ~38 HU) with irregular arterial phase enhancement (CT value ~136 HU) and decreased venous phase enhancement (CT value ~92 HU). Tortuous renal arteries were observed traversing the mass, and non-enhancing areas within the mass suggested necrosis. The right ureteral tumor exhibited uneven enhancement, raising suspicion for malignancy.
Figure 1
Given the patient’s bilateral urinary system involvement and advanced age, one-stage surgical management was deemed high risk. Therefore, a staged surgical approach was planned to balance oncological outcomes and preserve renal function after comprehensive consideration. The patient and his family consented to and accepted our proposed treatment plan.
First, the patient underwent laparoscopic partial nephrectomy for the left renal mass on June 19. Postoperative pathology revealed one tumor measuring approximately 6.55*4 cm in size, with a golden gray–white cut surface and a soft texture. The focal areas are gelatin-like (Figure 1E). Microscopically, the tumor was confirmed as clear cell renal cell carcinoma (CCRCC) with focal rhabdoid differentiation, WHO/ISUP grade 4 (Figures 2A, C). The immunohistochemistry results were as follows: EMA (+), RCC marker (+), CD10 (+), Vimentin (+), CK7 (-), P504S (focally +), CD117 (-), Ksp-cad (-), TFE3 (focally weak +), CAIX (+), Ki-67 (active area approximately 50% +), and PAX8 (+). Uneventfully, the patient recovered and was discharged on June 30.
Figure 2
Renal dynamic imaging and glomerular filtration rate (GFR) testing prior to the second surgery revealed a total GFR of 62.2 mL/min, with the left kidney at 31.5 mL/min and the right kidney GFR at 30.7 mL/min. The surgery was performed on July 26, involving laparoscopic unilateral nephroureterectomy for the right ureteral tumor. Postoperative pathology revealed a 1.6×1.1 cm pedunculated smooth mass located 14 cm from the ureteral resection margin (Figure 1F). Microscopic examination and immunohistochemistry confirmed it as a metastasis of CCRCC, with no cancer involvement at the ureteral resection margin (Figures 2B, D).
The patient recovered well and was discharged on August 5. At the fourteen-month follow-up, no evidence of metastasis or other abnormalities was observed. Besides, no special discomfort symptoms have been reported since the last operation.
Discussions
This is an exceptionally rare case, and we have reviewed the limited number of reported cases reported globally. Typically, the clinical presentation of such cases includes hematuria, as observed in our patient. Early imaging tests, particularly contrast-enhanced CT and urography, play a pivotal role in diagnosis. When a renal tumor is found on one side and a ureteral mass with hydronephrosis on the contralateral side, the possibility of contralateral ureteral metastasis from renal cancer cannot be ignored.
Currently, there is no standardized treatment protocol given the rarity of this condition. Our management strategy is to first address the renal tumor and then address the ureteral side lesion. The optimal treatment for stage T1 renal cancer is partial nephrectomy (), which can effectively reduce damage to renal function and shorten convalescence. The long-standing standard treatment for upper tract urothelial carcinoma (UTUC) is radical nephroureterectomy, which is the safest method for minimizing the risk of recurrence, although the damage to patients’ renal function is huge. According to the European Association of Urology (EAU) risk stratification tool for UTUC, our case could be classified into the high-risk group, for which radical nephroureterectomy is recommended as the preferred option, as we performed (). Hence, for this patient, a left partial nephrectomy was performed first to ensure a quicker recovery so that the patient was able to undergo a contralateral radical nephroureterectomy only one month later. However, if we addressed the ureteral lesion first, the operative trauma would have been greater, and the recovery would have been longer, which may have led to the progression of the CCRCC and potentially missed the optimal timing for a partial nephrectomy.
The impact of our surgical approach on renal function is inevitable. However, we have taken concerted measures to minimize this effect. For instance, we maintained close renal function monitoring during follow-up and collaborated with the nephrology department to implement targeted improvements through medication and lifestyle management. Over the recent follow-ups, the patient’s renal function has remained stable, with no observed progressive deterioration. Whereas, the EAU guidelines on UTUC also suggest considering nephron-sparing surgery for patients with a solitary kidney and/or impaired renal function, which is noteworthy for patients with RCC with contralateral ureteral metastasis. In our case, the patient’s renal function was impaired after partial nephrectomy. Thus, whether nephron-sparing surgery on the contralateral side can be an option is discussable. If this surgery was to be performed, then cytological examination is necessary, such as preoperative ureteroscopic biopsy or rapid intraoperative pathology, which contributes to clarifying the tumor’s pathological characteristics and determining its risk accurately though it should be noticed that ureteroscopic biopsy for UTUC might increase the risk of intravesical recurrence (). Other limitations of ureteroscopic biopsy include possible missed diagnoses or inaccurate staging due to insufficient sampling (, ), as well as the risk of tumor dissemination caused by high intraluminal pressure, mucosal injury, or ureteral perforation during the procedure (, ). Owing to the scarcity of similar cases and the lack of long-term follow-up, the safety of nephron-sparing surgery alone remains to be verified.
One noteworthy aspect in our case is the pathological finding. While no mention of rhabdoid differentiation was found in the reported similar cases, this differentiation occurs in 4–6% of RCC overall, and its frequency increases to over 27% in high-grade (WHO/ISUP grade 4) RCCs (–). This morphological pattern is linked to early metastasis and poor prognosis (, , ). Although less aggressive than sarcomatoid differentiation (), its presence in our case likely contributed to the contralateral ureteral metastasis. While VHL inactivation is the primary driver of clear cell renal cell carcinoma, our study did not include in-depth research like genetic analysis of the tumor. This represents one of the limitations of our study. Current evidence shows that rhabdoid differentiation often involves additional high-grade mutations, such as co-occurring BAP1 and PBRM1 alterations (). Therefore, conducting fundamental researches in such cases would be valuable for understanding tumor pathogenesis and investigating potential targets for treatment. Hence, we propose creating a multi-institutional registry to systematically identify and manage these rare cases. This initiative will not only create opportunities for fundamental research but also facilitate the collection of comprehensive clinical data, ultimately enhancing our understanding of the disease’s pathogenesis and refining clinical management strategies.
Conclusions
We report a case of postoperatively confirmed unilateral renal clear cell carcinoma with synchronous contralateral ureteral metastasis, which is an extremely rare occurrence. Our treatment approach involved firstly management of the renal tumor, followed by the contralateral ureteral tumor. Although the huge damage to the patient’s renal function is inevitable, the advantage of this approach is that it ensures optimal safety and minimizes the interval between surgeries, thus preventing progression of the disease.
Statements
Data availability statement
The original contributions presented in the study are included in the article/Supplementary Material. Further inquiries can be directed to the corresponding author.
Ethics statement
Written informed consent was obtained from the individual(s) for the publication of any potentially identifiable images or data included in this article.
Author contributions
YQ: Writing – review & editing, Writing – original draft. YL: Writing – review & editing. QZ: Writing – review & editing. JX: Resources, Writing – review & editing, Supervision. HS: Resources, Funding acquisition, Writing – review & editing, Supervision. JD: Writing – review & editing, Supervision, Resources.
Funding
The author(s) declared that financial support was received for this work and/or its publication. This research was supported by the Suzhou Clinical Medical Center Program (grants Szlcyxzx202106).
Conflict of interest
The authors declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Generative AI statement
The author(s) declared that generative AI was not used in the creation of this manuscript.
Any alternative text (alt text) provided alongside figures in this article has been generated by Frontiers with the support of artificial intelligence and reasonable efforts have been made to ensure accuracy, including review by the authors wherever possible. If you identify any issues, please contact us.
Publisher’s note
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.
References
1
BianchiMSunMJeldresCShariatSFTrinhQDBrigantiAet al. Distribution of metastatic sites in renal cell carcinoma: a population-based analysis. Ann Oncol. (2012) 23:973–80. doi: 10.1093/annonc/mdr362
2
HughesMAArkellDGDawson-EdwardsPGeddesJR. Contralateral ureteric metastasis from renal carcinoma. Br J Urol. (1976) 48:402–. doi: 10.1111/j.1464-410X.1976.tb06667.x
3
EsrigDSteinJPKamellosAWKiyabuMFreemanJAAhleringTE. Metastatic renal cell carcinoma to the contralateral ureter. Urology. (1994) 44:278–81. doi: 10.1016/s0090-4295(94)80151-7
4
PearceI. Synchronous presentation of primary renal adenocarcinoma and contralateral ureteric metastasis. J Clin Pathol. (2000) 53:639–40. doi: 10.1136/jcp.53.8.639
5
Al-BusaidySSGeorgeKKamonaASamarasingheDS. Renal cell carcinoma: synchronous contralateral ureteric metastasis. Br J Med Surg Urol. (2011) 4:86–8. doi: 10.1016/j.bjmsu.2010.02.006
6
ReidSLArestisNJMcIlhennyCLambGWA. Contralateral renal cell carcinoma ureteric metastases can arise on tyrosine kinase adjuvant therapy and be effectively treated by endoscopic laser excision and ablation. Case Rep Urol. (2014) 2014:1–3. doi: 10.1155/2014/359352
7
LeeKHLaiW-HChiuAW-SLuC-CHuangSK-H. Robot-assisted retroperitoneoscopic surgery for synchronous contralateral ureteral metastasis of renal-cell carcinoma. J Endourol Case Rep. (2015) 1:65–7. doi: 10.1089/cren.2015.0023
8
Kammerer-JacquetS-FBrunotAPladysABouzilleGDagherJMedaneSet al. Synchronous metastatic clear-cell renal cell carcinoma: a distinct morphologic, immunohistochemical, and molecular phenotype. Clin Genitourin Cancer. (2017) 15:e1–7. doi: 10.1016/j.clgc.2016.06.007
9
LjungbergBAlbigesLAbu-GhanemYBedkeJCapitanioUDabestaniSet al. European Association of Urology guidelines on renal cell carcinoma: the 2022 update. Eur Urol. (2022) 82:399–410. doi: 10.1016/j.eururo.2022.03.006
10
RouprêtMSeisenTBirtleAJCapounOCompératEMDominguez-EscrigJLet al. European Association of Urology guidelines on upper urinary tract urothelial carcinoma: 2023 update. Eur Urol. (2023) 84:49–64. doi: 10.1016/j.eururo.2023.03.013
11
SharmaVMiestTSJuvetTSToussiAPackiamVChamieKet al. The impact of upper tract urothelial carcinoma diagnostic modality on intravesical recurrence after radical nephroureterectomy: a single institution series and updated meta-analysis. J Urol. (2021) 206:558–67. doi: 10.1097/ju.0000000000001834
12
MargolinEJMatulayJTLiGMengXChaoBVijayVet al. Discordance between ureteroscopic biopsy and final pathology for upper tract urothelial carcinoma. J Urol. (2018) 199:1440–5. doi: 10.1016/j.juro.2018.02.002
13
BaardJCormioLDasguptaRMaruzziDRais-BahramiSSerranoAet al. Unveiling the challenges of UTUC biopsies and cytology: insights from a global real-world practice study. World J Urol. (2024) 42:177. doi: 10.1007/s00345-024-04866-w
14
LimDJShattuckMCCookWA. Pyelovenous lymphatic migration of transitional cell carcinoma following flexible ureterorenoscopy. J Urol. (1993) 149:109–11. doi: 10.1016/s0022-5347(17)36014-7
15
JohnsonDBPearleMS. Complications of ureteroscopy. Urol Clin North Am. (2004) 31:157–71. doi: 10.1016/s0094-0143(03)00089-2
16
Chapman-FredricksJRHerreraLBrachoJGomez-FernandezCLeveilleeRReyLet al. Adult renal cell carcinoma with rhabdoid morphology represents a neoplastic dedifferentiation analogous to sarcomatoid carcinoma. Ann Diagn Pathol. (2011) 15:333–7. doi: 10.1016/j.anndiagpath.2011.03.002
17
KimHInomotoCUchidaTKajiwaraHKomiyamaTKobayashiHet al. Impact of rhabdoid differentiation on postoperative outcome for patients with N0M0 renal cell carcinoma. Urol Oncol. (2019) 37:711–20. doi: 10.1016/j.urolonc.2019.05.012
18
ZhangBYChevilleJCThompsonRHLohseCMBoorjianSALeibovichBCet al. Impact of rhabdoid differentiation on prognosis for patients with grade 4 renal cell carcinoma. Eur Urol. (2015) 68:5–7. doi: 10.1016/j.eururo.2015.01.002
19
AdeniranAJShuchBHumphreyPA. Sarcomatoid and rhabdoid renal cell carcinoma. Am J Surg Pathol. (2024) 48:e65–88. doi: 10.1097/pas.0000000000002233
20
PrzybycinCGMcKenneyJKReynoldsJPCampbellSZhouMKarafaMTet al. Rhabdoid differentiation is associated with aggressive behavior in renal cell carcinoma: a clinicopathologic analysis of 76 cases with clinical follow-up. Am J Surg Pathol. (2014) 38:1260–5. doi: 10.1097/pas.0000000000000251
21
KaraOMauriceMJZargarHMalkocEAkcaOAndradeHSet al. Prognostic implications of sarcomatoid and rhabdoid differentiation in patients with grade 4 renal cell carcinoma. Int Urol Nephrol. (2016) 48:1253–60. doi: 10.1007/s11255-016-1314-z
22
KapurPPeña-LlopisSChristieAZhrebkerLPavía-JiménezARathmellWKet al. Effects on survival of BAP1 and PBRM1 mutations in sporadic clear-cell renal-cell carcinoma: a retrospective analysis with independent validation. Lancet Oncol. (2013) 14:159–67. doi: 10.1016/s1470-2045(12)70584-3
Summary
Keywords
renal cell carcinoma, ureteral neoplasms, metastasis, nephroureterectomy, nephrectomy, biopsy
Citation
Qian Y, Lu Y, Zhang Q, Xie J, Shen H and Deng J (2026) Case Report: A rare case of unilateral renal clear cell carcinoma with synchronous contralateral ureteral metastasis. Front. Oncol. 15:1616814. doi: 10.3389/fonc.2025.1616814
Received
23 April 2025
Revised
04 November 2025
Accepted
18 December 2025
Published
09 January 2026
Volume
15 - 2025
Edited by
Alessandro Tafuri, Ospedale Vito Fazzi, Italy
Reviewed by
Rajesh Kumar, Kerala University of Health Sciences, India
Hani Hour, Beit Jala Governmental Hospital, Palestine
Updates
Copyright
© 2026 Qian, Lu, Zhang, Xie, Shen and Deng.
This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Junpeng Deng, djunpeng@outlook.com
Disclaimer
All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.