Left atrial thrombus mimicking a myxoma in a patient with systemic lupus erythematosus.

Atrial masses are uncommon, and mainly consist of tumors, vegetations and thrombi. Despite the availability of several imaging modalities, it may still be difficult to distinguish between them. Atrial thrombi seen in patients with systemic lupus erythematosus (SLE) usually occur in the setting of anti-phospholipid antibody syndrome, which confers a hypercoagulable state. We report a case of left atrial thrombus mimicking a myxoma in a patient with SLE but negative anti-phospholipid antibodies.