Primary lung tumor mimicking acute type A aortic dissection.

A 64-year-old man presented with clinical features and echocardiographic diagnosis of an acute type A dissection. He underwent median sternotomy for definitive surgical treatment. On external examination of the aorta, other intrapericardial structures, and the right lung, it was evident that the patient had an advanced lung tumor. This was confirmed by frozen-section and histopathologic examinations. Epiaortic scanning showed beyond doubt the presence of a mobile intraaortic mass that had misled us in making the preoperative diagnosis of an acute type A dissection.