Background In rare cases of pulmonary embolism, large thrombemboli have been found entrapped in a patent foramen ovale (PFO). Case Description A patient was referred to our center with leg swelling and dyspnea. Electrocardiogram showed sinus tachycardia and right axis deviation. Echocardiography revealed a highly mobile biatrial thrombus entrapped in a PFO extending to both tricuspid and mitral valves and prolapsing into the left ventricle. Urgent surgery for cardiac thrombectomy and PFO closure was performed. Intraoperatively, massive coherent thrombus material was extracted. Conclusion Because of a lack of data, decision making has to rely on clinical judgment rather than evidence.
