Abstract
BACKGROUND: Cardiac involvement in malignancies is rare, with right ventricular tumoral thrombus in hepatocellular carcinoma (HCC) without right atrial extension being exceptionally uncommon. CASE SUMMARY: A 54-year-old man with stage IV HCC experienced recurrent chest discomfort. Stress echocardiography detected an ill-defined inhomogeneous mass, and cardiac magnetic resonance identified right ventricular outflow tract obstruction, left ventricular septal infiltration, and acute-to-subacute myocarditis. Abdominal imaging showed tumor recurrence along with a large thrombus in the retrohepatic inferior vena cava. After multidisciplinary discussions, the patient opted for palliative comfort care. DISCUSSION: Systemic therapy for HCC such as atezolizumab-bevacizumab and lenvatinib may contribute to thrombosis, cardiac dysfunction, and myocarditis. Currently, there are no established guidelines for managing right ventricular tumoral thrombus with outflow tract obstruction complicated by myocarditis, which if untreated could lead to irreversible ventricular dysfunction. CONCLUSIONS: This case highlights the significance of shared decision-making and a multidisciplinary patient-centered approach in optimizing treatment outcomes in complex cardio-oncology care.