Retrocaval thymus

Retrocaval thymus is defined as an ectopic location of thymus between the superior vena cava and great arteries. It is a rare finding and mostly asymptomatic.

Radiographic features

Plain radiograph
  • may mimic mediastinal mass or right upper lobe collapse
CT and MRI
  • soft tissue that is consistent in appearance with and contiguous with a normally positioned thymus