Angiosarcomas of the interatrial septum mimicking atrial myxomas.

Angiosarcoma of the heart is a rare tumor. This tumor is most frequently located in the right atrium and pericardium. Localization of a tumor in the interatrial septum usually suggests atrial myxoma. We report two cases of angiosarcoma originating from the interatrial septum, one extending into the right atrium and the other into the left atrium, mimicking atrial myxomas. Transesophageal echocardiography allowed the diagnosis and comprehensive assessment of compromised structures.