Mediastinal lipomatosis. CT confirmation of a normal variant.

Mediastinal lipomatosis is a common benign cause of mediastinal widening. While it may be associated with exogenous obesity, steroid ingestion, or Cushing's syndrome, these factors often are not present. Evaluation of the mediastinum by CT should be the initial diagnostic study in the work-up of patients with abnormalities of the mediastinal contour; indeed, in many cases it can eliminate the need for other procedures.