Ruptured thoracic aneurysm presenting as dyspnea and hypotension.

A 65-year-old woman with a two-day history of progressive back pain presented with acute dyspnea, tachypnea, hypotension, and tachycardia. The patient was being treated for chronic obstructive lung disease and long-standing hypertension. She evidenced unilateral diminished breath sounds and wheezing. A portable chest radiograph in the emergency department revealed a large left pleural effusion. A hemothorax was confirmed by thoracentesis, and a 7-cm descending thoracic aortic aneurysm was demonstrated by angiography. The patient underwent successful surgical resection and Dacron graft repair of the aneurysm. This case emphasizes the need for maintaining a high index of suspicion for atypical presentations of ruptured thoracic aneurysms and for using diagnostic thoracentesis in pleural effusions of unknown etiology.