There is a large mass in the right hemithorax appearing contiguous with the cardio-mediastinal contour on this side. The right pulmonary vasculature is seen behind the mass. There is no mediastinal shift. In particular, there is no tracheal displacement. Left lung is clear. There is no pleural effusion on either side.
This was felt to represent a normal thymus, likely asymmetric. An ultrasound was subsequently performed to confirm the above.