The atrial mass without an auscultatory “plop”: renal cell carcinoma presenting with cardiac syncope—a case report

Introduction

Renal cell carcinoma (RCC) is one of the most common malignancies in the United States, with clear cell RCC being the most common type diagnosed (1). Patients typically present with a triad of hematuria, flank pain, and a palpable abdominal mass as well as nonspecific symptoms such as fatigue and weight loss (1). RCC can invade into the ipsilateral renal vein, inferior vena cava (IVC) less commonly, and cause cardiopulmonary instability. Particularly, extension of RCC tumor thrombus into the right atrium is rare and complex. This extension is typically associated with significant morbidity and mortality, making early recognition and prompt intervention critical. The rarity of this presentation means that it is often not immediately considered in patients with atypical cardiovascular symptoms.

In the present study, we describe a rare case of RCC with extension of the tumor thrombus into the IVC and right atrium causing syncope. We present this article in accordance with the CARE reporting checklist (available at https://acr.amegroups.com/article/view/10.21037/acr-25-6/rc).

Case presentation

The patient is a 65-year-old gentleman with a past medical history of essential hypertension, coronary artery disease, benign prostate hyperplasia, obstructive sleep apnea, acid reflux, recent episode of hemoptysis, and non-ST-segment elevation myocardial infarction (NSTEMI) status post drug eluting stent to right coronary artery (RCA) and left anterior descending (LAD) presented after a syncopal episode. Patient states that the syncopal episode was triggered by the exacerbating activity of running on the treadmill after a 3-month extended period of not exercising. This attempt to turn off the treadmill was his last memory.

Vitals showed a blood pressure of 131/76 mmHg, heart rate of 79 bpm, and respiratory rate of 16 breaths per minute. He was afebrile (36.4 ℃) with an oxygen saturation of 95% on room air. A cardiovascular exam revealed a normal rate and regular rhythm with no murmur, no auscultatory plop, no jugular venous distension, and no lower extremity edema. The chest wall was non-tender to palpation. The abdominal exam was negative for organomegaly or abdominal masses. There were no other significant physical exam findings. No reported hematuria, dysuria or urinary incontinence. No varicocele.

Electrocardiogram revealed normal sinus rhythm without any ischemic changes. The initial troponins were critically elevated at 0.14 and 0.29 ng/mL, with a delta troponin of +0.15 ng/mL. However, based on past medical records, his troponins are chronically elevated. B-type natriuretic peptide was elevated at 1,449 pg/mL.

Transthoracic echocardiography (TTE) revealed a severely reduced systolic function, estimated ejection fraction of 60–65%, right atrium showed a large mass. Transesophageal echocardiography (TEE) revealed a severely reduced systolic function, estimated ejection fraction is 55–60%, severely dilated right atrium with large, 4.9 cm (length) × 4.6 cm (width), hyperechoic, highly vascular but also cystic highly mobile mass extending from the IVC into the right atrial cavity (Figures 1,2). Using Definity, no stalk was seen. There was increased uptake of Definity concerning a highly vascular malignant process.

Figure 1 Trans-esophageal echocardiogram mid-esophageal bicaval view showing a large, exophytic, lobulated mass echo-bright mass with extension from the IVC into the right atrium. The mass measures 4.9 cm × 4.61 cm. IVC, inferior vena cava.

Figure 2 Trans-esophageal echocardiogram mid-esophageal bicaval view showing a large, exophytic, lobulated mass echo-bright mass with extension from the IVC into the right atrium. Color Doppler flow exhibits flow around the mass, consistent with solid mass within the right atrium. IVC, inferior vena cava.

Computed tomography (CT) of chest, abdomen and pelvis without contrast revealed a large exophytic lobulated heterogeneously enhancing solid mass related to the central and medial aspect of the right kidney measuring 14.7 cm × 12.8 cm × 10.2 cm in longitudinal, anterior-posterior, and transverse dimensions (Figures 3,4). Several necrotic areas with this mass most likely represent right RCC. There is extensive heterogeneous tumor thrombus in the right renal vein and throughout the expanding suprarenal IVC and intrahepatic IVC as well as into the right atrium of the heart. Perinephric collaterals present. There is a 3.4 cm × 2.3 cm posterior interpolar level left renal cyst. CT also revealed expansile and extensive heterogeneous tumor thrombus involving the right renal vein, suprarenal IVC, intrahepatic IVC and partially into the right atrium. CT also revealed bilateral pulmonary nodules suspicious for pulmonary metastatic disease, 1.1 cm. CT also revealed heterogeneous tumor thrombus extends throughout the suprarenal IVC and into the right atrium and incidental extensive acute pulmonary emboli bilaterally at the bilateral pulmonary arteries and bilateral lobar and segmental branches (Figures 5-7). Evidence of right heart strain with an increased right ventricle and left ventricle ratio.

Figure 3 CT of chest, abdomen and pelvis without contrast, coronal view, revealed a large exophytic lobulated heterogeneously enhancing solid mass related to the central and medial aspect of the right kidney measuring 14.7 cm × 12.8 cm × 10.2 cm in longitudinal, anterior-posterior, and transverse dimensions. CT, computed tomography.

Figure 4 CT of chest, abdomen and pelvis without contrast, sagittal view, revealed a large exophytic, lobulated, heterogeneously enhancing solid mass related to the central and medial aspect of the right kidney. CT, computed tomography.

Figure 5 CTA of chest revealed a nearly occlusive thrombus in the distal right main pulmonary artery. CTA, computed tomography angiography.

Figure 6 CTA of chest revealed a pulmonary thrombus in the distal left main pulmonary artery into the bifurcation of the lobar branches. CTA, computed tomography angiography.

Figure 7 High resolution lung CT revealed a peripheral lateral lung nodule in the left lower lobe measuring 1.1 cm. CT, computed tomography.

Therapeutic intervention

The patient was started on intravenous fluids to maintain euvolemia and a heparin drip for anticoagulation due to tumor thrombus and bilateral pulmonary emboli. He was urgently transferred to a local tertiary care facility for higher-level care and intervention. An abdominal magnetic resonance imaging (MRI) revealed a 14.8 cm × 8.8 cm × 8.9 cm mass centered in the medial aspect of the right kidney, extending into the right renal vein, IVC, and right atrium, consistent with RCC. He underwent a surgical procedure to address the right renal tumor, involving excision of the atrial and IVC tumor, a radical right nephrectomy, and caval reconstruction utilizing cardiopulmonary bypass and hypothermic circulatory arrest. The surgery was completed without complications, and he was transferred to the intensive care unit (ICU) in stable condition. At diagnosis, there was concern for metastatic disease to his lungs, but was recommended to follow up with the oncologist in the outpatient setting. He was discharged home with recommendations for anticoagulation therapy (apixaban), aspirin, and a statin. At a follow-up visit with his cardiologist 6 months later, he was successfully undergoing chemotherapy for metastatic RCC while continuing anticoagulation with apixaban, along with aspirin, a statin, and a beta-blocker.

Re-staging CT performed following surgery demonstrated progression of pulmonary nodules consistent with metastatic RCC. The patient began combination immunotherapy with ipilimumab and nivolumab (ipi/nivo) at Cycle 1 Day (C1D1) and Cycle 2 Day 1 (C2D1). However, due to concerns regarding possible complications and adverse effects, ipi/nivo therapy was held and the patient was started on prednisone 100 mg. A follow-up CT performed several months later revealed new solid pulmonary nodules and a new soft tissue lesion in the tail of the pancreas. The patient declined biopsy of the pancreatic lesion, and it was decided that the next-line empiric RCC therapy of axitinib would be started.

All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patient for the publication of this case report and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Discussion

RCC is a common cancer diagnosis in the United States with a poor prognosis. In the year of 2020, over 400,000 patients were newly diagnosed with RCC and there were 180,000 associated deaths (1). Given the clinical significance of this disease, early detection and management is paramount for improving patient health outcomes.

The initial presentation of RCC is classically known to be a triad of flank pain, palpable abdominal mass and hematuria. These symptoms manifest due to localized mass effect. In 65% of the cases, RCC is diagnosed while the disease is localized (2). However, 16% of patients are diagnosed with regional lymph node involvement and 16% of the patients are diagnosed with metastatic disease (2). Interestingly, despite the 14.7 cm × 12.8 cm sized solid renal mass, our patient did not present with any of the classically associated symptoms. Instead, our patient presented to the emergency department for the symptom of syncope. This case is interesting because it presents a unique presentation of RCC and provokes a re-evaluation of our approach to syncope.

Syncope is not a commonly associated initial presenting symptom for RCC. The American College of Cardiology defines syncope as the clinical pattern of a sudden loss of consciousness due to transient cerebral hypoperfusion followed by rapid spontaneous revival. Cardiovascular syncope occurs due to decreased cardiac output and resultant cerebral hypoxia due to structural deformities or arrhythmias. After ruling out obstructive coronary artery disease with cardiac catheterization, we attributed this episode of cardiac syncope to right ventricular failure from the atrial mass and extensive pulmonary embolism (PE). Given that this patient’s syncopal episode occurred during exercise, it is likely related to the increased cardiometabolic demand associated with physical exertion. The resulting reduction in cerebral perfusion may be attributed to the right atrial mass, which occupied a significant portion of the right atrium as seen on TEE, or the extensive pulmonary emboli identified on CT in combination with impaired adequate perfusion under hyperdynamic conditions.

RCC is vascular malignancy that is prone to vascular invasion and thrombotic complications. In 5–15% of cases, RCC can lead to the formation of a tumor thrombus, which is an intravascular tumor extension (2). RCC can directly invade the renal vein and IVC and extend within the vasculature. This extension process can propagate up to the right atrium and lead to the formation of an atrial mass and PE (1,2). In 10% of cases, patients with RCC can have the added complication of cavoatrial involvement (3). Tumor cells often express initiators of the coagulation cascade and tissue factor (TF), which can contribute to blood coagulation and extension of the thrombus (1). On TEE and CT abdomen and pelvis, it was evident that this patient developed a tumor thrombus that originated in the right kidney and propagated to the right atrium. This patient likely developed a tumor thrombus in his right atrium, which contributed to the right heart strain and culminating presentation of syncope.

PEs are a common etiology for cardiac syncope. PE is classically known to present with overt symptoms of resting dyspnea, tachypnea, hypoxia, tachycardia, and pleuritic chest pain (4). However, our patients denied all these symptoms during the period leading up to the admission. Instead, this patient’s extensive PE was found incidentally on CT. Although syncope is not commonly associated with PE, it is important to recognize that syncope may be the only presenting symptom for PE (4). The development of this PE is likely a composite of the multiple components having a stacking effect. Our case, the tumor thrombus is likely the main mechanism for the PE. PE is formed by the activation of the coagulation system by the tumor cells products of pro-coagulant factors and inflammatory cytokines and the direct contact between the tumor cells and endothelial cells and blood cells (4). This hypercoagulative state increases the risk for the development of a PE. This obstruction by the PE lead to an increased right ventricle to left ventricle ratio and right ventricular strain.

Conclusions

In conclusion, we report a case RCC that presented with syncope due to the formation of a tumor thrombus with cavoatrial involvement and extensive PE. This case was unique because of the atypical presentation of a patient with RCC and PE. This case emphasizes the importance of broadening our differential with approaching patients with cardiac syncope. Given the severity of these disease processes, early detection and diagnosis is key to improved patient outcomes.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the CARE reporting checklist. Available at https://acr.amegroups.com/article/view/10.21037/acr-25-6/rc

Peer Review File: Available at https://acr.amegroups.com/article/view/10.21037/acr-25-6/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://acr.amegroups.com/article/view/10.21037/acr-25-6/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patient for the publication of this case report and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

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