Vascular Tracheobronchial Compression Syndrome Secondary to Contained Ruptured Thoracic Aortic Aneurysm.

On CTA, the patient was found to have a large saccular aneurysm measuring 5.0 × 5.0 × 5.0 cm, arising from a focal location of the proximal descending thoracic aorta distal to the origin of the left subclavian artery with evidence of contained rupture. The mass was found to be causing significant external compression of the left main bronchus leading to significant effacement of the left main primary bronchi leading to extensive collapse in both left upper and lower lobes and overall reduction in volume of the left hemithorax.