Multimodality Imaging of a Mass Arising from a Cor Triatriatum Sinister Membrane.

Cor triatriatum sinister is a rare entity characterized by a membrane within the left atrium and posterior to the atrial appendage. This defect may cause obstructive symptoms analogous to mitral stenosis. The authors present a case of an incidentally detected enhancing mass originating from a cor triatriatum sinister membrane, with imaging characteristics most suggestive of myxoma. Keywords: MR Imaging, Cardiac, Left Atrium, Congenital, CT Angiography, Echocardiography Supplemental material is available for this article .