Surgical management of the patient with metastatic melanoma to the heart

Metastatic melanoma of the heart: Retrospective cohort study and systematic review of prevalence, clinical characteristics, and outcomes

BACKGROUND

Cardiac metastasis of melanoma is rare and typically diagnosed post-mortem. Here we perform a retrospective cohort study and systematic review of patients with metastatic melanoma to characterize prevalence, clinical characteristics, and outcomes of cardiac metastasis.

METHODS

We reviewed the electronic medical records of all outpatients with metastatic melanoma who underwent evaluation at the University of Michigan in Ann Arbor from January 2009 to January 2022, identifying patients with a clinical or histopathologic diagnosis of cardiac metastasis. We performed a systematic review of the literature to summarize the clinical characteristics and outcomes of patients with melanoma and cardiac metastasis.

RESULTS

Overall, 23 of 1254 (1.8%) patients with metastatic melanoma were diagnosed with cardiac metastasis. Cardiac metastasis was reported in the right ventricle (65%), left ventricle (35%), and right atrium (35%). A total of 11 (48%) patients experienced at least one cardiovascular complication after the diagnosis of cardiac metastasis, the most common being arrhythmia (30%), heart failure (22%), and pericardial effusion (17%). Immunotherapy was more commonly used in patients with cardiac metastasis (80% vs 65%; p = 0.005). Mortality at 2-years post-diagnosis was higher for patients with cardiac metastasis compared to those without (59% vs 37%; p = 0.034). Progression of malignancy was the underlying cause of death of all patients.

CONCLUSIONS

Cardiac metastasis occurs in <2% of patients with metastatic melanoma, can affect all cardiac structures, and is associated with various cardiovascular complications and high mortality.

Atypical Cardiac Location of Melanoma of Unknown Origin

The subject was a 66-year-old woman, suffering from the chest pain evoked by physical activity. Transthoracic echocardiography (TTE) revealed an abnormal structure, 41 × 29 mm. In MSCT, a hypodensic mobile tissue lesion that was infiltrating the whole thickness of left ventricle was confirmed. PET excluded the existence of other remote lesions. After surgical tumor removal, histopathological differential diagnosis revealed melanoma, myoepithelial cancer, and MPNST “high–grade” sarcoma. A control TTE detected a tumor that was 14 × 10 mm. After immunohistochemical results, immunotherapy with pembrolizumab was used, which resulted in complete tumor resolution. Presently, surgical resection and neoadjuvant targeted immunochemotherapy remain the treatment of choice for clinical stage III/IV melanoma.

Immunotherapy for Metastatic Melanoma with Right Atrial Involvement in a Patient with Rheumatoid Arthritis

Prognosis for metastatic melanoma has improved significantly with the use of immune checkpoint inhibitors. Given improvements in survival, aggressive surgical treatment may be considered in patients with life-threatening complications from their disease that would not otherwise be considered in advanced disease. Patients with preexisting autoimmune diseases or prior immune-related adverse events from therapy are largely excluded from clinical trials. Concerns exist that immunotherapy in these patients could worsen autoimmune disease or increase the risk of developing additional immune-related adverse events on therapy. We present a case of a patient with rheumatoid arthritis that presented with obstructive heart failure secondary to melanoma that had metastasized to the right atrium. After aggressive surgical resection to stabilize him from his life-threatening heart failure, he was treated with ipilimumab, which was stopped due to an immune-related adverse event. He was then started on pembrolizumab and had a durable response to therapy. Aggressive surgical treatment should be considered in patients with a cancer that may respond to immunotherapy. Furthermore, some patients with preexisting autoimmune disease may be safely treated with checkpoint inhibition therapy, and patients with a severe immune toxicity from one class may successfully be treated with an alternate class.

Right atrial metastatic melanoma with unknown primaries

A 54-year-old male with history of anemia and rheumatoid arthritis presented with a three-month history of dyspnea on exertion and lower extremity edema. Patient was referred for a transthoracic echocardiogram that revealed a large right atrial mass with reduced ejection fraction of 40% and an incidental large liver mass. Subsequent cardiac MRI revealed a lobulated right atrial mass measuring 5.4 cm × 5.3 cm with inferior vena cava compression and adjacent multiple large liver lesions confirmed to be malignant melanoma through biopsy. Interestingly, no primaries were found in the patient. PET/CT imaging displayed hypermetabolic masses within the right atrium and liver that likely represent metastases, as well as bilateral pleural effusions, most likely due to heart failure. Preoperative coronary angiogram demonstrated perfusion to the mass by a dense network of neovasculature arising from the mid right coronary artery. The cardiac melanoma was surgically removed, and the right atrium was reconstructed with a pericardial patch. After surgery, all cardiac chambers appeared normal in size and function with associated moderate tricuspid regurgitation. The patient is currently being administered ipilimumab for systemic therapy of metastatic melanoma.