A rare giant asymptomatic biatrial myxoma

The left atrial myxoma is the most common type in clinical practice, whereas biatrial myxomas are extremely rare (less than 3%). Over the past five decades, approximately 50 cases of biatrial myxoma have been reported in the literature. Here, we report a rare, large, asymptomatic biatrial myxoma, involving the inferior vena cava (IVC) and part of the posterior wall of the left atrium (LAPW).

In this case, a 75-year-old elderly woman was incidentally found to have a biatrial myxoma with atrial flutter after chest trauma. Further evaluation with cardiac computed tomography angiography (CTA) was performed on patient for delineating the tumor's size, morphology, attachment site, extension, internal enhancement characteristics, and to rule out concomitant coronary artery disease. Intraoperative findings showed the tumor extended into the IVC and the LAPW. Finally, the patient underwent surgical resection of the tumor under cardiopulmonary bypass (CPB), along with excision of the left atrial appendage, and we reconstructed LAPW and IVC. The patient recovered uneventfully and was discharged on postoperative day 10. At a 5-month follow-up, no recurrence of atrial myxoma was observed.

Biatrial myxoma is extremely rare and sometimes can be challenging to diagnose. Currently, there are no guidelines or consensus statements regarding the best diagnostic methods. Based on our case, we suggest that computed tomography (CT) and cardiac CTA can provide sufficient details about diagnostic value in cases where transthoracic echocardiography (TTE) fails to provide a clear diagnosis. Surgery is mandatory once cardiac myxoma is diagnosed. In cases of giant cardiac myxomas involving the IVC and the LA, careful preoperative planning is required, including venous cannulation for CPB and reconstruction of cardiac structures after complete tumor excision.