INCIDENTAL DISCOVERY OF A RIGHT ATRIAL MASS: KEY ROLE OF MULTIMODALITY IMAGING IN DIAGNOSING A CARDIAC LIPOMA

Background: Cardiac lipomas are rare benign tumors that are frequently discovered incidentally and may mimic other intracardiac masses, particularly thrombi or malignant tumors. Accurate non-invasive tissue characterization is essential to guide appropriate management and avoid unnecessary interventions.
Case summary: We report the case of an 87-year-old man referred for evaluation of an incidentally detected right atrial mass. Transthoracic echocardiography demonstrated a well-defined mobile intracavitary lesion, initially raising suspicion of thrombus. Cardiac magnetic resonance (CMR) provided comprehensive tissue characterization, revealing a well-circumscribed fatty mass with markedly reduced native T1 values, absence of first-pass perfusion, and no late gadolinium enhancement, findings highly suggestive of a cardiac lipoma. Whole-body ^18F-FDG PET/CT showed no abnormal metabolic activity, further supporting the diagnosis of a benign lesion. Given the absence of significant symptoms, hemodynamic compromise, or imaging features suggestive of malignancy, a conservative management strategy with regular imaging follow-up was adopted. 
Conclusion: This case highlights the pivotal role of multimodality imaging, particularly CMR complemented by FDG PET/CT, in the non-invasive diagnosis of cardiac lipoma. An integrated imaging approach allows reliable differentiation from thrombi and malignant cardiac tumors, facilitating appropriate patient management while avoiding unnecessary surgery in carefully selected asymptomatic patients