[A case of vagus nerve schwannoma in the middle mediastinum presenting with dyspnea].

A 67-year-old woman complaining of dyspnea was referred to our hospital because of an abnormal chest radiography shadow. Computed tomographic (CT) scans as well as magnetic resonance images (MRI) demonstrated a mid-mediastinal mass of 9 cm in diameter, surrounded by the superior vena cava (SVC), the ascending aorta, the azygos vein arch and the trachea at the subaortic level. The left main bronchus was stenotic, probably because of expansion of the tumor, which seemed to be the cause of the dyspnea.