Left atrial appendage mass.

Left atrial (LA) masses are known to be associated with peripheral embolization. Accurate identification of etiology is crucial because treatment strategies may differ. We present the case of a young woman, who was initially diagnosed with a LA thrombus and anticoagulated. The diagnosis was revised to a primary cardiac tumor after review of the echocardiographic findings. Surgical excision revealed an atrial myxoma in an unusual location.