This case demonstrates a type I IVC aneurysm (Gradman and Steinburg classification). Most of these IVC aneurysms are idiopathic. Some are congenital, while others are caused by trauma or arteriovenous fistulae. The suprahepatic variant of these aneurysms is usually discovered as an incidental mass in the lower mediastinum, just behind the heart.

Patients are usually asymptomatic, but occasionally an aneurysm may be the site of thrombus formation.

Case courtesy: Prof. Fabio Denicolò