Abstract 4370855: Biventricular Cardiac Metastasis of Cutaneous Melanoma: Imaging-Guided Treatment Strategy with Check-Point Inhibition and Debulking Surgery

Background: Melanoma frequently spreads hematogenously, yet cardiac metastases remain under-recognized and carry high mortality. Early identification and coordinated cardio-oncology management may improve functional outcomes. Case: A 59-year-old woman underwent resection of CDK4-positive, BRAF/KIT/NRAS-negative >cutaneous melanoma of the left thigh and foot. Four months later, an 18F-FDG PET-CT (figure 1) revealed disseminated disease with intense pericardial uptake. Cardiac MRI (figure 2) showed a 3.3 cm right-ventricular (RV) free-wall mass and a 1.1 cm left-ventricular (LV) apical lesion; transthoracic echocardiography (TTE) (figure 3) confirmed mass location with preserved biventricular function. Decision-Making/Intervention: A heart–oncology team initiated nivolumab + ipilimumab (4 × q3 wk, every 3 weeks) followed by maintenance nivolumab. Therapy induced widespread metabolic remission and LV mass resolution but paradoxical RV-mass enlargement, causing exertional dyspnea, orthopnea, and edema. After coronary angiography excluded ischemia, the patient underwent RV debulking with resection of two large tumors, multiple implants, and a right-atrial thrombus; intra-operative transesophageal echocardiography (TEE) confirmed tricuspid-valve integrity. Outcome Pathology verified metastatic melanoma. Post-operative TTE showed complete RV mass removal and normalized filling; symptoms resolved, and the patient resumed maintenance immunotherapy. At 5-month follow-up, she remained New York Heart Association (NYHA) class I with no residual tumor on imaging. Conclusion: Multimodal imaging unmasked occult biventricular melanoma, guided immunotherapy, and informed the timing of palliative-to-therapeutic surgical debulking. Early multidisciplinary engagement facilitated hemodynamic recovery and durable oncologic control, offering a pragmatic framework for managing cardiac metastases in the era of checkpoint inhibitors.