Direct entry of the right superior vena cava into the left atrium with aneurysmal dilatation and stenosis at its entry into the right atrium with stenosis of the pulmonary veins: a rare case.

This is the first autopsied case reported in the English language literature wherein the right superior vena cava entered both atria with obstruction of the entry into the right atrium, aneurysmal dilatation of the proximal part of the superior vena cava, and entry of the stenosed right upper pulmonary vein into the aneurysmal sac. The aneurysmally dilated right superior vena cava communicated directly with the left atrium. In addition, the remainder of the pulmonary veins, all of which were markedly stenosed, entered the left atrium. The embryogenesis of this unique malformation is briefly discussed.