SUMMARY A case of right atrial myxoma is reported in a 29-year-old man. Though it was a large tumour, the diagnosis remained unsuspected for a long time.Multiple echo recordings strongly contributed to the diagnosis. After surgical removal, the postoperative course was uneventful.Since Banhson and Newman first described surgical removal of a right atrial myxoma, the importance of the recognition of these tumours has been widely emphasised.This report presents a case where echocardiography proved very useful in establishing the diagnosis. Case report A 29-year-old man was referred to the cardiological department in October 1976, for worsening dyspnoea and arthralgia.The past history disclosed that for 18 months he had been complaining of cough, palpitation, and fever (37.5-38°C); on chest x-ray examination, the heart was enlarged and the electrocardiogram showed ST-T changes; he was thus thought to have pericarditis and underwent biopsy of the pericardium which showed only non-specific fibrosis.On admission, his blood pressure was 130/80 mm Hg. Neck veins were not distended. A grade 2/6 protosystolic murmur and a grade 2/6 diastolic murmur were heard at the left sternal border; both were increased by inspiration.The electrocardiogram showed sinus rhythm, incomplete right bundle-branch block, and diffuse ST-T changes. The chest film showed cardiomegaly with right ventricular enlargement.The laboratory findings were a high erythrocyte sedimentation rate (35 mm in 1 hr, Wintrobe) and a white blood cell count of 13 200 with 80 per cent neutrophils. The other blood chemistry values were within the normal range.Echocardiography was then performed (Echeovideorex-CGR-2-25 MHz.) Fig. 1 shows intracardiac echoes, anterior to a 20] normal aorta, and originating from the right ventricular outflow tract, which are recorded by a beam passing through the aortic root. These echoes were identified only during the second part of diastole. An M mode-scan (Fig. 2) shows the right ventricular diastolic echoes which are identified in the mitral as well as in the aortic recordings. Left heart echograms are normal.Right heart catheterisation was also performed. The shape of the right atrial pressure curve suggested tricuspid regurgitation (giant v wave); the mean pressure was 9 mmHg and increased to 17 mmHg during compression of the liver. The right ventricular pressure was 25/0-5 mmHg.Cineangiographic studies with injection into the inferior vena cava showed a filling defect within the right atrium ( Fig. 3a and b). The mass was seen to prolapse into the right ventricle during ventricular diastole and return into the right atrium near the inferior vena cava during ventricular systole.With a presumptive diagnosis of right atrial myxoma, the patient was submitted to open-heart surgery. Operative findings consisted of a large myxoma attached to the interatrial septum between the inferior vena cava and the coronary sinus orifices by a stalk 2 mm in length. The tumour was removed and an associated dilatation of the tricuspid orifice was cor...