Parachute-like sinus venosus remnant: echocardiographic and pathological appearance.

A female infant with multiple congenital abnormalities and a right atrial "mass" on echocardiography is reported. Her general condition at birth was poor, and the chest x-ray showed cardiomegaly. Echocardiography demonstrated the usual atrial arrangement and concordant atrioventricular and ventriculoarterial connections with a mobile right atrial mass. Death occurred at 3 days of age and subsequent postmortem examination revealed a hollow, tube-like sinus venosus remnant mobile between right atrium and ventricle with numerous other abnormalities of the heart, including left heart hypoplasia and tubular hypoplasia of the aortic arch. Filling of the sinus venosus remnant with blood had resulted in an echocardiographic appearance suggestive of a right atrial tumor.