P404Atrial mass: what is typical does not appear always typical

Funding Acknowledgements: Aswan Heart Center Introduction: Cardiac masses are not uncommon findings in the clinical practice. However, systematic imaging approach should be meticulously applied to avoid misdiagnosis of these cardiac masses. Herewith, we presented a referred patient with a diagnosis of right atrium (RA) myxoma which turned out not to be. We are highlighting the role of systematic CMR imaging protocol in reaching the correct the diagnosis. Case Report: 30-year-old male presented by mild dyspnea, fatigue. He had a Left ventricle (LV) pseudoaneurysm that had been surgically repaired 2 years ago. On auscultation there was a left lower sternal border ejection systolic murmur. Transthoracic Echocardiogram (TTE) revealed spherical highly mobile mass, located within right atrium, attached by a pedicle to interatrial septum (IAS), showing hyperechogenic periphery & hypoechoic core. The initial diagnosis was right side myxoma. Patient was referred to CMR unit for tissue characterization of this mass. CMR was performed on 1.5 T scanner .CMR protocol included cine SSFP images to localize the mass, T1 black blood, T2 black blood with fat suppression, first pass perfusion images and late gadolinium enhancement (LGE) images for tissue characterization CMR confirmed the TTE findings of right atrial mass with smooth surface measuring 2.3X1.6 cm attached by a pedicel to the IAS not obstructing the tricuspid valve. The mass showed no vascularity on first pass perfusion and on late gadolinium enhancement with long TI the mass was jet black and it was isointense on T1 black blood sequences, there was also transmural scar of lateral wall and thrombus the same site of previously repaired LV pseudoaneurysm. These criteria does not fit with the referred diagnosis as myxoma and mostly it was a thrombus in the RA Discussion: Right atrial mass is challenging diagnosis associated with different spectrum of management. In our case the right atrial thrombus looks typical like myxoma by TTE but using CMR give us the true and definite diagnosis. Many studies countered right atrial thrombus identical to myxomas and the best modality of differentiation is tissue characterization by CMR. Conclusion: Systemic CMR approach of cardiac masses is the best modality to reach the correct diagnosis. Abstract P404 Figure. CMR Systemic approach of RA mass