Left atrial myxofibrosarcoma: Diagnostic approach through imaging techniques

Primary cardiac sarcomas are rare. A 63-year-old woman presented with progressive symptoms of fatigue, palpitations, and dyspnea. Transthoracic echocardiography detected a mass in the left atrium, fixed and probably attached to the interatrial septum suggestive of myxoma. Transesophageal echocardiography confirmed the existence of a large lobulated mass in the left atrium measuring 45 mm × 25 mm in diameter. Subsequent cardiac magnetic resonance imaging showed a mass of heterogeneous appearance, with broad base of implantation on the posterior wall of the left atrium. The extension study with multidetector computed tomography showed superficial infiltration of the atrial wall, without involvement of the mitral valve or pulmonary veins and no extension to other extracardiac structures. The patient underwent surgery resecting a bilobed mass, smooth and yellowish, strongly attached to the posterior wall of left atrium. The pathologic study was consistent with the diagnosis of myxofibrosarcoma.