1| INTRODUCTION
Giant cardiac myxoma is a rare disease that occurs in 3–4% of cases and is associated with pulmonary embolism in only 0.1% to 0.6% of cases [1,2,3], which can lead to cardiac arrest, accompanied by acute heart failure, affecting the patient’s health. We report a case of a giant right ventricular myxoma being separated into pulmonary thrombus simultaneously in the process of Transthoracic echocardiography. The young man underwent intracardiac repair immediately according to ultrasonic suggestion and was doing well.
2| CASE PRESENTATION
An 18-year-old young man performed physical examination before college entrance examination. Transthoracic echocardiography (TTE) showed: a heterogeneous mass was found in the right ventricle, a 40 mm wide pedicle, occupying 2/3 chamber of right ventricle, 86 mm×65mm×49 mm in irregular papillary shape.(Fig. 1A–C, Supplementary file:Video 1 and 2). With the heart beating, one end of the mass swung back and forth to right atrium through the tricuspid valve, the other end swung to right ventricular outflow tract simultaneously (Supplementary file: Video 1 and 2). There was no obvious dilation of pulmonary trunk and its, branches. CDFI: the mass has no obvious blood flow signals. A small amount of regurgitation at the tricuspid orifice during systole was observed with 2.4 m/s peak flow velocity and 24 mmHg pressure gradient (Fig. 1D). The blood flow velocity of pulmonary artery valve orifice was 0.98m/s during diastole, with no obvious backflow. (Supplementary file: Video 3) . the patient suddenly felt the symptoms of chest pain and dyspnea, and TTE demonstrated the mass maybe a myxoma, and it was detached simultaneously. Electrocardiogram showed complete right bundle branch block.
Emergency lung Contrast-enhanced CT and Pulmonary artery CT (CTPA) was performed for the patient as following, 7.0 cm×4.3 cm mass with no contrast enhancement was showed with Contrast-enhanced CT (Fig. 1E) . About 3.2 cm×1.6 cm nodular filling defect was found in the right inferior pulmonary artery, and the blood perfusion in the right lower lung was decreased with CTPA(Fig. 1F) . There has no obvious abnormality with CT of carotid artery and cerebral artery, there was no lower extremity deep venous thrombosis with point-of care Ultrasonography. blood gas and biochemical parameters were normal. Immediately, an emergency treatment of ”cardiac tumor resection + pulmonary thrombectomy + tricuspid valvuloplasty” were successfully performed for the patient, the right ventricular myxoma and pulmonary tumorous embolus were showed during the operation (Fig. 1G-I) . So many primitive blood vessels were found in the myxoid matrix, CD34 was strongly positive stained (Fig. 1J–L ), All the results suggested that the mass was myxoma. Of course, the patient has been followed-up for half a year with no signs of recurrence of myxoma and pulmonary embolism.