[Right Atrial Blood Cyst with Patent Foramen Ovale:Report of a Case].

A woman in 70s was diagnosed with lung cancer, and a right atrial mass was discovered incidentally during preoperative examination by contrast-enhanced computed tomography (CT). Transesophageal echocardiography revealed a 20-mm, stemmed, spherical mass with low internal echogenicity and partially high echogenicity extending from the junction of the inferior vena cava to the posterior wall of the right atrium. Patent foramen ovale( PFO) was also confirmed. To avoid embolization and obtain diagnosis, the patient was referred for right atrial tumor resection. Cardiopulmonary bypass was established; the right atrial tumor was removed while the patient was in cardiac arrest. The tumor membrane was thin and easily ruptured, revealing jelly-like blood content and calcified mass. The patient recovered well after surgery and was discharged on day 15. According to the pathological examination, the tumor was a blood cyst. This is an extremely rare case of a blood cyst with PFO.