Abstract
Background
Renal cell carcinoma is associated with tumor thrombus that can extend into the inferior vena cava and right atrium, representing risk of massive pulmonary embolism.
Case Summary
A 60-year-old woman was diagnosed with renal cell carcinoma. Computed tomography imaging demonstrated a heterogeneous mass extending from the right renal vein into the right ventricle in keeping with tumor thrombus. On transthoracic echocardiogram, the tumor thrombus can be seen to prolapse into the right ventricle with diastole. Surgical extraction was discussed but ultimately not performed. At 6 weeks post diagnosis, the tumor thrombus had organized and become more homogeneous. At 12 weeks post diagnosis, the patient remained well without signs of thromboembolism.
Discussion
We present a case of increasing organization and size reduction of medically managed extensive renal cell tumor thrombus on interval echocardiography.
Take-Home Message
In cases in which surgical extraction is unsuitable, risk of tumor thrombus extension or thromboembolism may reduce with anticoagulation.
Key Words: cardio-oncology, echocardiography
Visual Summary
Visual Summary.
Interval Echocardiography of Medically Managed Extensive Intracardiac Renal Cell Tumor Thrombus
Timeline of the events from presentation and diagnosis of renal cell carcinoma to incidental finding of tumor thrombus extending into the right atrium on computed tomography (CT). Subsequent echocardiography demonstrates the tumor thrombus before and after 6 weeks of anticoagulation. The mass has reduced in size and become organized.
History of Presentation
A 60-year-old woman initially presented to her general practitioner with persistent lower back pain and reduced appetite with 4 kg unintentional weight loss. She denied chest pain, dyspnea, or fevers. Physical exam demonstrated a split S1 heart sound. Measured vital signs did not demonstrate hemodynamic or respiratory distress. The practitioner referred her for an urgent ultrasound of her abdomen that showed a large 12 × 11 × 12-cm right flank mass.
Past Medical History
Her past medical history included dyslipidemia, asthma, and iron deficiency anemia.
Differential Diagnosis
The combination of renal mass and unintentional weight loss is suspicious for malignancy. Primary malignancies of the kidney include renal cell carcinoma and transitional cell carcinoma. A distal metastasis from a primary melanoma or lymphoma, as well as benign lesions such an angiomyolipoma or renal cyst, also remained within the differential.
Investigations
The patient was admitted to hospital and a computed tomography scan of her thorax, abdomen, and pelvis showed a heterogeneous, enhancing renal mass measuring up to 12 cm with central necrosis and surrounding neural vascularization. Focal thrombus was seen in the right renal vein. A dimercaptosuccinic acid scan showed a percentage relative total uptake of 88.5% in the left kidney and 11.5% on the right. Multiple small rounded pulmonary nodules suggested metastatic disease. A biopsy of the renal mass was performed that confirmed clear cell renal cell carcinoma. Treatment with ipilimumab and nivolumab induction dosing was initiated and the patient was discharged with a regular visit to the oncology department for immunotherapy infusions.
The patient then attended for a restaging scan after 2 months of treatment that demonstrated extension of the tumor thrombus from her right renal vein, ascending up the inferior vena cava into the right atrium, in addition to new hilar, intralobar, and intralobular lymphadenopathy (Figure 1). The patient was re-admitted and a transthoracic echocardiogram demonstrated a large thrombus in the right atrium prolapsing into the ventricle with diastole (Video 1). Despite the sizable volume of the atrium occupied by the tumor thrombus and the partial occlusion of the tricuspid valve, the patient reported only mild dyspnea. Physical exam was negative for peripheral edema or an elevated jugular venous pressure. N-terminal pro–B-type natriuretic peptide returned at 1,906 pg/mL. A computed tomography pulmonary angiogram demonstrated no embolism to the pulmonary arteries.
Figure 1.
CT Imaging of Thrombus
Coronal reconstruction of the computed tomography scan of the thorax, abdomen, and pelvis with contrast, obtained for staging after 2 months of immunotherapy. (A) Large right renal mass with continuous tumor thrombus extending via a markedly expanded inferior vena cava. (B) Sagittal reconstruction with longitudinal extent of the tumor thrombus into the right atrium (Mayo level IV). Arrows indicate findings.
Management
Oral anticoagulation with apixaban 5mg BD was added to ongoing nivolumab and ipilimumab induction dosing. The imaging findings were discussed at the urology multidisciplinary meeting with regard to a possible thrombectomy with nephrectomy. The benefits and risks were discussed with the patient including the high-risk nature of surgical intervention. Given the expected prolonged recovery period, the metastatic nature of the disease, and new lymphadenopathy, which was felt to represent progression, the decision was made not to pursue surgical extraction in the first instance.
Outcome and Follow-Up
The patient had regular medical review with physical examination and routine blood testing during her regularly scheduled immunotherapy infusions. She remained asymptomatic and free from signs of congestive cardiac failure or pulmonary embolism. A serial echocardiogram was performed 6 weeks after the initial transthoracic echocardiography that showed a smaller more homogeneous thrombus. At time of review 3 months post diagnosis, the patient remained subjectively well without chest pain or significant dyspnea.
Discussion
It is estimated that 4% to 10% of patients will have renal cell tumor thrombus at time of diagnosis1 and it is associated with larger tumors and more distant metastasis.2 The reported prevalence of extension is 10% to 18% invading the renal vein, 4% to 23% reaching the inferior vena cava, and 1% extending into the right atrium.3 Although the accepted standard of treatment is radical nephrectomy with tumor thrombectomy, surgical mortality is estimated to be around 2% to 10%4
In this case, the tumor thrombus had extended to the point of prolapsing through the tricuspid valve into the right ventricle. Although the mass had not caused significant hemodynamic instability, further propagation may lead to flow obstruction through the tricuspid valve. There is also a substantial risk for massive pulmonary embolism. Color flow was seen across the interatrial septum suspicious for a patent foramen ovale, representing a potential for paradoxical embolism into the systemic circulation. These risks must be balanced against the risk of intraoperative and postoperative complications. Furthermore, the impact of recovery on the patient’s quality of life must be considered, particularly in cases with progression of oncological disease despite medical therapy.
Advanced disease and high risk of intraoperative complications may support a decision to pursue medical management. In the absence of randomized controlled trials, risk estimation can be challenging. If surgical extraction is not performed, not only is there a risk of a large pulmonary embolism, but also micro metastatic seeding of the pulmonary system by the tumor cells present in the mass. No randomized controlled trial has demonstrated benefit of anticoagulation and as such guidelines do not recommend for or against their use.
The inhibition of thrombus propagation with anticoagulation is an established principle in the treatment of pulmonary embolism.5 Unfortunately, it is unknown whether a similar effect applies to tumor thrombus. Clinicians may have concern with regard to a reduction in the structural integrity of the lesion, potentially predisposing patients to downstream embolic phenomena, of particular importance for large caval or intracardiac lesions. The interval organization seen in this case suggests increasing structural integrity.
To our knowledge, this is the first reported case demonstrating interval echocardiographic imaging of increased homogeneity and reduction in size of an intracardiac tumor thrombus with anticoagulation.
Funding Support and Author Disclosures
The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
Take-Home Message
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This case demonstrates that in extensive renal cell tumor thrombus in patients with advanced disease, medical management may result in tumor thrombus organization and reduction in size.
Footnotes
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the Author Center.
Appendix
For supplemental videos, please see the online version of this paper.
Appendix
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(A) Echocardiogram at time of staging scan 8 weeks post diagnosis demonstrates tumor thrombus in right atrium prolapsing into right ventricle. (B) Echocardiogram at 14 weeks post diagnosis, after 6 weeks of anticoagulation. The tumor thrombus is more homogenized and has reduced in size.
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Timeline of the events from presentation and diagnosis of renal cell carcinoma, to incidental finding of tumor thrombus extending into the right atrium on computed tomography. Subsequent echocardiography demonstrates the tumor thrombus before and after 6 weeks of anticoagulation. The mass has reduced in size and become organized.
References
- 1.Martínez-Salamanca J.I., Huang W.C., Millán I., et al. International renal cell carcinoma-venous thrombus consortium. Prognostic impact of the 2009 UICC/AJCC TNM staging system for renal cell carcinoma with venous extension. Eur Urol. 2011;59(1):120–127. doi: 10.1016/j.eururo.2010.10.001. [DOI] [PubMed] [Google Scholar]
- 2.Zisman A., Wieder J.A., Pantuck A.J., et al. Renal cell carcinoma with tumor thrombus extension: biology, role of nephrectomy and response to immunotherapy. J Urol. 2003;169(3):909–916. doi: 10.1097/01.ju.0000045706.35470.1e. [DOI] [PubMed] [Google Scholar]
- 3.Kaptein F.H.J., van der Hulle T., Braken S.J.E., et al. Prevalence, treatment, and prognosis of tumor thrombi in renal cell carcinoma. JACC CardioOncol. 2022;4(4):522–531. doi: 10.1016/j.jaccao.2022.07.011. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Uroweb - European Association of Urology EAU guidelines on RCC - DISEASE MANAGEMENT - Uroweb. 2026. Accessed April 10, 2026. https://uroweb.org/guidelines/renal-cell-carcinoma/chapter/disease-management
- 5.Kahn S.R., de Wit K. “Pulmonary Embolism”. N Engl J Med. 2022;387:45–57. doi: 10.1056/NEJMcp2116489. [DOI] [PubMed] [Google Scholar]
Associated Data
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Supplementary Materials
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(A) Echocardiogram at time of staging scan 8 weeks post diagnosis demonstrates tumor thrombus in right atrium prolapsing into right ventricle. (B) Echocardiogram at 14 weeks post diagnosis, after 6 weeks of anticoagulation. The tumor thrombus is more homogenized and has reduced in size.
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Timeline of the events from presentation and diagnosis of renal cell carcinoma, to incidental finding of tumor thrombus extending into the right atrium on computed tomography. Subsequent echocardiography demonstrates the tumor thrombus before and after 6 weeks of anticoagulation. The mass has reduced in size and become organized.