P1460 Atrial myxoma with atypical location in an asymptomatic patient

Abstract

Abstract Introduction Primary cardiac tumours are rare. Most of them are benign, among which myxomas are the most common. Usually they occur in the left atrium (75%) but there are cases of right atrial myxomas. The majority of patients with atrial myxoma present with one or more symptoms of clinical triad of embolic events, intracardiac obstruction, or nonspecific manifestations. We report a rare case of cardiac myxoma arising from the right atrium as an accidental finding during routine medical checkup. Case report A 52 years-old woman was admitted to ambulatory care for a general checkup. At presentation, her heart rate was 82 bpm, regular and blood pressure was 150/90 mmHg. Other investigative results were normal. Her ECG showed normal sinus rhythm. She was sent for a routine echocardiography to judge for further treatment of the arterial hypertension. Transthoracic echocardiogram showed normal left ventricular ejection fraction. There was a mobile echogenic mass of nearly 6 cm2 in the right atrium, prolapsing through the tricuspid valve with mild tricuspid regurgitation without causing obstruction and protruding into the inferior vena cava (IVC). The transesophageal echocardiographic examination confirmed the presence of a mobile multilobular mass in the right atrial free wall close to the IVC origin. A total body angio-CT scan showed an intraatrial mass measuring approximately 5 × 4 cm, without infiltration of the adjacent structures, suggesting the diagnosis of myxoma. Coronary angiography revealed normal coronary arteries. The patient underwent median sternotomy under general anesthesia. The tumor was completely excised through a right atriotomy. The resected mass was sent for histological assessment which confirmed the diagnosis of myxoma. Discussion RA myxomas usually originate in the fossa ovalis or base of the interatrial septum, but in this case, the myxoma was implanted in the atrial inferior vena cava junction. Myxomas are usually polypoid and pedunculated tumors (approximately 83% of cases). In this report, our patient had a solitary, pedunculated mass with polypoid areas and a lobulated surface. Echocardiography remains the best diagnostic method for locating and assessing the extent of myxomas and for detecting their recurrence, with a sensitivity of up to 100%. However, transthoracic echocardiogram may not identify tumors smaller than 5 mm in diameter, and a transesophageal echocardiogram is required when there is suspicion of a very small tumor. In this case, an echocardiogram suggested the hypothesis of RA myxoma, which was confirmed by a histopathological exam. Myxomas are friable with high chance of systemic or pulmonary embolization depending on tumour location. Early diagnosis and timely surgical resection is the treatment of choice to prevent possible fatal consequences such as sudden death. Abstract P1460 Figure. Right Atrial Myxoma