RESUMEN
We report a case of a 28 year old female who presented to us in November 2016 with a swelling in front of neck for three years and worsening shortness of breath for last one year, causing right sided tracheal deviation and mildSuperior Vena Caval obstruction. X-ray showed a soft tissue density mass in antero-superior mediastinum with cephalad extension. Contrast enhanced CT neck and chest revealed a multi cystic lesion extending from the root of neck to anterior mediastinum causing compression and deviation of trachea, and nearby structures especially Superior Vena Cava (SVC) along with collateral formation. Mass was surgically excised from the neck and mediastinum with uneventful post-operative recovery. Histopathology was consistent with benign mature cystic teratoma.