A right atrial mass was incidentally detected in an immunosuppressed 49-year-old woman 5 years after successful bilateral lung transplantation. The mass was surgically excised and found to be an organized thrombus. There was no clear mechanism for the de-novo thrombus formation. The potential mechanisms include immunosuppression-related thrombogenicity, transient pericarditis, and stasis of blood from persisting pulmonary hypertension.
