A Unique Case of a Right Atrial Myxoma Infected With Escherichia coli

A 70-year-old white male, with past medical history of coronary artery disease, peripheral arterial disease status-post bilateral femoral artery stents, insulin-dependent diabetes mellitus, hypertension, hyperlipidemia, arthritis, tobacco use, and alcohol use, presented with shortness of breath and an abnormal finding on a recent transesophageal echo. This had revealed a large, fixed mass in the right atrium. Our differential diagnosis had included thrombus, endocarditis, myxoma, papillary fibroelastoma, sarcoma, and metastatic tumor. The cardiothoracic surgeon excised this mass, which upon culturing, revealed what we found to be the only reported case of an atrial myxoma infected with Escherichia coli. In addition to surgical excision, the patient was treated with six weeks of intravenous cefepime.