In a patient presenting of this age with shortness of breath as the main presenting complaint, malignancy often becomes one of the likely diagnosis. In this case, however, CT aortogram showed a large aneurysm of the proximal descending thoracic aorta with a type B aortic dissection. The large pleural effusion on the left was highly likely to be secondary to rupture/leaking of thoracic aortic aneurysm. The patient was diagnosed with chronic aortic dissection and was for palliative measures upon discussion with the vascular team.

This case highlights the importance of always considering other differentials in addition to your provisional diagnosis, both clinically and radiologically.