| A 46-year-old male non-smoker pre-sented to the emer-gency department with multiple epi-sodes of syncope and resting dyspnea. He reported worsening dyspnea on exertion for the past 4 months. Electrocardiogram showed normal sinus rhythm with non-spe-cific ST-T changes in V1–V4. Echocar-diography showed a large mass obliterating most of the right ventricular cavity and extending to the tri-cuspid leaflets, resulting in severe tricuspid stenosis with turbulent flow across the valve (Figure A, Videos 1, 2*). Continuous wave Doppler recording over the tricuspid valve showed mean diastolic gradient of 9.6 mmHg and peak gradient of 18.3 mmHg (Figure B). Left ventricular function was normal. In view of his symptoms, the patient underwent urgent surgery for resection of the tumor. In surgery, the right ventricle tumor was found to originate from the endocardium of the interventricular septum and extended to the tricuspid valve (Figure C, D). There was chordal in-volvement. The right ventricular free wall was free of tumor. The tumor was resected and the tricuspid valve was replaced with St. Jude bileaflet prosthesis. Postoperative course was uneventful. Histological ex-amination of the tumor showed polygonal and stel-late cells surrounded by abundant loose stroma rich in acid mucopolysaccharides. Direct cardiac muscu-lar invasion and abnormal mitoses were not found. Immunohistochemical staining showed strong im-munoreactivity for CD31. Moreover, while the cells over the vascular boundaries were stained with CD34 antigen, they remained negative for calretinin. Typi-cal histologic features indicated myxoma (Figure E-H). At 12-month follow-up, echocardiography showed no evidence of recurrence (Video 3*). |