Multimodality Imaging of a Right Atrial Cardiac Mass

Work up of a right atrial mass usually requires multimodality imaging and sometimes a biopsy to affirm histological diagnosis. We present a case of a 74-year-old woman with primary cutaneous melanoma (wildtype BRAF) of the right toe who was found to have a large heterogeneous mass in the right atrium on routine surveillance CT scan. She did not have any cardiac symptoms. Vital signs and physical examination were unremarkable. Cardiac magnetic resonance (CMR) imaging demonstrated a bilobed mass with an intramural component and a mobile blood pool component, with interposed thrombus. Three-dimensional transesophageal echocardiogram (3D-TEE) revealed the mass and its site of attachment on the lateral wall of the right atrium. Given the large size of the tumor and its potential for obstruction of tricuspid inflow, the right atrial mass was surgically resected. Pathology confirmed metastatic melanoma. The patient tolerated cardiac surgery well and was discharged shortly thereafter. In the present case, a large cardiac metastasis was discovered in the absence of clinically detectable disease elsewhere. CMR allowed a comprehensive evaluation of the location, extension, and tissue characterization of the cardiac mass. Transthoracic echocardiogram (TTE) and 3D-TEE allowed assessment of the hemodynamic consequences of this mass and aided in operative planning.