The chest x-ray shows widening of the superior mediastinum with a bulge on the right suggestive of abnormally dilated ascending aorta.

This patient underwent a CT scan of the chest which showed an ascending aortic aneurysm measuring 10 cm in diameter. There was no contrast leak to suggest rupture and there was no dissection. The patient underwent emergent surgery.

Ascending aortic aneurysm is defined as dilatation of the ascending aorta more than 4cm (radiopaedia).