Renal clear cell carcinoma with atrial myocardial, pericardial, and superior vena cava metastases sparing the inferior vena cava

A 72-year-old male presented with an incidental 5 cm right renal mass involving para-aortic and retrocaval nodes. Biopsy revealed a high-grade renal cell carcinoma (RCC). Cytoreductive nephrectomy with limited retroperitoneal lymph node dissection was performed and confirmed a 55 mm clear cell RCC with renal vein involvement and positive surgical margins (pT3aN1). Pazopanib was commenced for 3 months with limited response, followed by nivolumab. Eighteen months post-operatively, the patient presented with exertional dyspnoea and syncope. CT identified a 49 × 29 mm lesion anterior to the superior vena cava (SVC) involving the right atrial (RA) appendage and new thoracic lymphadenopathy. In retrospect, the RA appendage lesion was present on CT 7 months prior, though smaller in size. Nivolumab was withheld temporarily. Two months later, investigation for progressive dyspnoea and syncope revealed the RA mass had grown to 58 × 33 × 56 mm with SVC extension (Fig. 1). Cardiac MRI identified mass extension to the level of pulmonary arterial bifurcation, causing partial SVC obstruction while sparing the IVC (Fig. 2). Concern for symptoms and imminent death from obstructive shock prompted recommendation for palliative debulking. Through median sternotomy, the tumour was visualized invading the pericardium overlying the RA and SVC junction and the left atrial roof. The mass left little space around the ascending aorta for cannulation or cross-clamping. Cardiopulmonary bypass was therefore instituted using the right common femoral artery, right common femoral vein and high SVC cannulation. The patient was cooled to 32°C. The cavae were snared and the heart was left beating. A right atriotomy resulted in direct tumour entry with tumour debulking. A bovine pericardial patch was used to augment the RA closure and minimize obstruction of the cavae to atrial flow. The patient was rewarmed to normothermia and weaned from cardiopulmonary bypass (total time 66 min). Histopathology later confirmed the cardiac lesion to be metastatic clear cell RCC. Heparin was commenced 6 h post-operatively, and aspirin was commenced 1 day post-operatively for the bovine pericardial patch. The patient's symptoms improved, and they were discharged on post-operative day 8 with palliative care services. After evaluating goals of care, nivolumab was ceased. Following an initial period of wellness, the patient developed fatigue and nausea from progressive metastatic disease. They were given best supportive care and passed away 3 months later. Up to a third of RCCs are metastatic at diagnosis.1 One percent of RCCs extend through the renal vein to the IVC and RA.2 Atrial wall metastasis without IVC involvement is rare.3 Despite recent advances in metastatic RCC treatment with tyrosine kinase inhibitors and immunotherapy,4 5-year survival remains poor at 12%.3 Three cases of RCC with septal and cardiac wall metastasis threatening obstructive shock that did not undergo intervention reported ranges of days to 3 months.2, 5, 6 Other cases report 8 months survival with stereotactic body radiotherapy to a septal lesion7 and 1 year survival with immunotherapy for myocardial, septal, and pericardial lesions.8 Generally, surgical management of RCC with multiple distant metastases does not lengthen survival.9 However, in this case, palliative debulking prevented imminent obstructive shock, relieved symptoms, and likely prolonged life in the short term. This rare case highlights the potential for RCC myocardial metastasis in the absence of IVC extension and describes options for palliative cardiothoracic debulking to prevent obstructive shock and prolong life. Informed consent was obtained from the patient to publish this article. Open access publishing facilitated by The University of Sydney, as part of the Wiley - The University of Sydney agreement via the Council of Australian University Librarians. Zoe R. Williams: Data curation; writing – original draft. James L. Kovacic: Investigation; writing – review and editing. Michael Seco: Investigation; writing – review and editing. David L. Chan: Investigation; writing – review and editing. Greta K. Beale: Investigation; writing – review and editing. Amanda S. Chung: Supervision; writing – review and editing. Ankur Dhar: Conceptualization; project administration; supervision; writing – review and editing. Matthew Winter: Investigation; supervision; writing – review and editing.