Abstract 12943: Malignant Melanoma Presenting as a Cardiac Tumor

Introduction: Melanoma is a neoplasm with a high propensity to metastasize to the heart. This report describes a case of widespread malignant melanoma with unknown primary diagnosed initially via screening echocardiography (TTE) during a health fair. Case report: A 54 year old Caucasian male patient (pt) with a history of rheumatoid arthritis underwent a screening TTE at a local health fair. At the health fair, he was told about a concerning finding seen on the TTE and instructed to follow-up with his primary care physician. Subsequently he underwent a repeat TTE which was suggestive of a large mass in the right atrium (7.4 x 4.5 cm) protruding through tricuspid valve (TV) into right ventricle. It was also suggestive of an incidental finding of a large liver mass (6 cm) with possible additional tumor invasion into the hepatic vein and the inferior vena cava. The pt was admitted to the hospital for further evaluation of this cardiac mass. Cardiac MRI showed a large lobulated right atrial mass with heterogeneous postcontrast enhancement, causing mass effect and prolapse, with concern for invasion of the TV and extension through the right atrial wall into the pericardium. Abdominal MRI showed multiple large liver masses. Thereafter, the pt underwent a liver biopsy consistent with metastatic melanoma. One month later, he developed worsening dyspnea on exertion and bilateral lower extremity edema. Subsequently, the pt was taken to the operating room and he underwent extensive resection of the right atrial mass with atrial reconstruction. Patient showed symptomatic improvement following the surgery. Discussion: Malignant melanoma carries a high tendency for cardiac involvement, although cardiac metastasis as the initial presentation is a rare clinical finding.