Background: Aneurysm of the fossa ovalis is an out pouching, space-occupying, interatrial septal structure. The anatomic morphology and characteristics of this aneurysm are of interest for pathologists and cardiologists alike.
Methods: We identified 33 specimens of adult hearts with a large size aneurysm of the fossa ovalis (length equal to or more than 10 mm from the plane of the atrial septum) in a registry of cardiovascular disease.