Background: Myxomas arising from the eustachian valve are exceedingly rare.
Case Report: A 72-year-old Jamaican- Chinese woman was evaluated for worsening dyspnea. The 2-dimensional and real time 3-dimensional transesophageal echocardiogram showed a 75 mm length × 44 mm width, multilobulated, mobile mass arising from the eustachian valve occupying the entire right atrial and right ventricular cavities extending into the coronary sinus, right ventricular outflow tract, and proximal inferior vena cava. The patient underwent successful resection of the mass and replacement of the tricuspid valve. Histopathologic examination confirmed the diagnosis of atrial myxoma.
Conclusions: This is the largest myxoma found on a Eustachian valve.

Keywords: Myxoma, eustachian valve, right atrial myxoma