Ruptured thoracic aortic dissection presenting as opacified left hemothorax

Acute aortic dissections are uncommon, with a reported incidence of 2000 cases per year in the United States. Hemothorax is an unusual but well-described complication of ruptured thoracic aortic dissection. It usually occurs on the left and can be seen in both proximal and distal dissections. Chest radiographs (CXR) in thoracic aortic dissections often reveal a widened mediastinum or abnormal aortic silhouette, evident in 80%-90% of cases. However, CXR may be normal in about 12% of patients with aortic dissection. Clues that would indicate aortic dissection such as abnormal aortic silhouette and widened mediastinum may be obscured by an opacified hemothorax caused by rupture of a thoracic aortic dissection. A high index of suspicion is necessary to make a diagnosis of ruptured thoracic aortic dissection in a patient presenting with hemothorax. This is illustrated in the case described.