AngioVac aspiration as a combined diagnostic and therapeutic strategy for an indeterminate right atrial mass in a patient with malignancy.

Right atrial masses in patients with active malignancy pose a diagnostic challenge, as imaging may not reliably distinguish thrombus from tumor and surgical biopsy may carry prohibitive risk. We report the case of a woman with primary mediastinal large B-cell lymphoma who was incidentally found to have a right atrial mass during evaluation for bacteremia. Transthoracic echocardiography (TTE), transesophageal echocardiography (TEE), and cardiac magnetic resonance imaging (MRI) suggested thrombus versus malignant involvement. Given high surgical risk, catheter-directed aspiration using the AngioVac system was performed, resulting in significant debulking and successful tissue retrieval without procedural complications. Histopathologic analysis confirmed fibrin thrombus without evidence of malignancy, allowing definitive diagnosis and guiding anticoagulation-based management. The patient's bacteremia resolved following central line removal and targeted antibiotic therapy. This case highlights the dual diagnostic and therapeutic utility of the AngioVac system in managing right-sided intracardiac masses when noninvasive imaging is inconclusive.