Giant aneurysm of the membranous ventricular septum extending outside the heart: diagnosis by transthoracic color flow Doppler echocardiography.

Aneurysm of the membranous ventricular septum (AMS) is a congenital cardiac anomaly often associated with ventricular septal defect. This aneurysm usually pouches into the right side of the heart and remains intracardiac. An AMS that extends outside of the heart is rare. We report an unusual case of a giant extracardiac AMS diagnosed by transthoracic color flow Doppler echocardiography.