Calcified mass in the right atrium extending into the inferior vena cava with pulmonary artery embolization. Typical or atypical myxoma?

ABSTRACT

Cardiac masses are divided into neoplastic and non-neoplastic. They usually represent a diagnostic challenge given their relative rarity, their infrequent symptoms, and the overall difficulty with dynamic imaging of the heart. While echocardiography is useful in the initial evaluation of a suspected mass, cardiac magnetic resonance (CMR) imaging is the best imaging modality to characterize cardiac tumors due to its superior tissue characterization and its higher contrast resolution. For neoplastic, primary cardiac tumors are rare (0.05%). Atrial myxoma is the most common cardiac (50%) mass. About 75%-80% of myxoma are seen in the left atrium. Atypical myxoma is a term describing myxoma arising in other nonleft atrial locations. 20%-25% myxomas arise from the right atrium and 5% or less from the ventricles. We present a case of a 59-year-old female patient presenting with severe dyspnea. Her chest noncontrast CT showed a calcified mass lesion in the right atrium extending into the inferior vena cava. She underwent cardiac MRI for better tissue characterization. The cardiac MRI revealed a very irregular, highly spiculated, heavily calcified, heterogeneous, and nonenhancing lesion within the right atrium extending into the inferior vena cava. Via dynamic imaging, no evidence of mobile components was present. Via T1, T2 along with pre- and postcontrast imaging, the mass was confirmed to be calcified without a fibrotic component or evidence of thrombus. The above findings raised the possibility of atypical myxoma.