<prompt> All are true about thymus swelling exceptWidening of mediastinum on XraySharp border with sail like appearanceSteroid administration reduces size of swellingShift of trachea on Xray  <response>: Thymic shadow does not indent tracheal shadow. A mediastinal shadow indenting tracheal shadow should always be evaluated for a significant pathology.Thymic swelling may cause widening of anterior mediastinum. Thymic swelling causes a sail-shaped shadow. Thymic swelling may shrink with use of steroids. 