[Widening mediastinum after blunt thoracic trauma: an unexpected differential diagnosis].

We report our experience concerning a young, white, healthy woman who had a typical blunt chest injury caused by a severe car accident. We had to evaluate and differentiate the initial roentgenographic post-traumatic mediastinal enlargement in order definitely to exclude a suspected covered rupture of the thoracic aorta or the heart caused by this high-velocity deceleration trauma. The difficulties encountered are critically discussed with regard to the unexpected primary thymoma that was diagnosed postoperatively. The diagnostic algorithm in blunt chest injury is also discussed. The controversy about the classification and management options of primary thymic tumors is also presented.