Cardiac melanoma: Retrospective review of a rare disease at the Mayo clinic (1988–2015)

Background Melanoma metastasizing to the heart (cardiac melanoma) is a rare entity that has been described only in autopsy studies or isolated pre-mortem case reports. We aim to better characterize cardiac melanoma, and describe its presenting features, imaging findings, and disease course with a case series collected over nearly 30 years. Methods We performed a retrospective review of all patients diagnosed with cardiac melanoma at the Mayo Clinic from 1988 to 2015. Qualitative analysis was performed on patient demographics, clinical history, and imaging modalities. Results 11 patients (7 male, median age 63 years) were identified with cardiac melanoma. Shortness of breath (64%) was the most common presenting symptom. Transthoracic echocardiography (TTE) was utilized in the assessment of all patients though it failed to identify 20% of masses that were seen on fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) or cardiac magnetic resonance (CMR). The majority of masses were located within the cardiac chambers (46% right atrium, 18% right ventricle, 18% left atrium), and 36% appeared mobile on TTE. Patients lived for a median of 68 months (interquartile range [IQR] 14–143 months) after the initial diagnosis of primary melanoma, and only 12 months (IQR 2–150 months) after diagnosis of cardiac melanoma. Conclusion Echocardiography can generally identify most cases of cardiac melanoma, though it misses one-fifth of masses seen on FDG PET/CT or CMR. Cardiac melanoma is associated with a poor prognosis.