Case report: Rapidly growing intra-cardiac mass mimicking a local recurrence of lung cancer or a thrombus in the left atrium

Cardiac myxoma typically is thought to be a slow-growing, benign primary. Atrial myxomas can lead to many complications and can also mimic mitral stenosis, infective endocarditis, and other vascular diseases associated with systemic embolization. A 75-year-old woman with a history of lung cancer (pT1cN1, adenocarcinoma), atrial fibrillation, and a cerebral infarction presented with dysarthria and visual disturbances. In our case, we had to consider some questionable issues with the left atrial mass, and whether the recurrence of cerebral events was due to the thrombotic material in the left atrium or from locally recurrent lung cancer from the stump margin of the previously resected left superior pulmonary vein. We present a case with a rapidly-growing left atrial myxoma with a growth rate of 12.60 mm/month, rather than a thrombus or local recurrence of tumor under a medication of non-VKA oral antagonists.