Remnants of the right valve of the sinus venosus presenting as a right atrial mass on transthoracic echocardiography.

Three patients were referred for suspicion of intracardiac tumour on transthoracic echocardiography. In all patients, the mass appeared as a nonobstructive oval structure measuring approximately 12 x 4 mm, located near the posterior third of the interatrial septum in the right atrium in the apical four-chamber view. The characteristics of the mass were not those of a Eustachian valve or a Chiari network. Multiplane transesophageal echocardiography performed in each of these patients did not reveal a tumour but rather a fibrous band in the right atrium, extending from the inferior to the superior vena cava. These findings are consistent with remnants of the right valve of the sinus venosus. Inclusion of a persistent right valve of the sinus venosus in the differential diagnosis of a right atrial mass can alleviate concern and spare an unnecessary transesophageal examination when the typical transthoracic echocardiographic characteristics are identified.