A vascular ring variant: an unusual case of vocal cord palsy due to an anomalous left carotid artery arising from a retrotracheal arch of the aorta.

We present the case of an unusual vascular ring in a 23-year-old male patient who presented for CT examination of the chest for diagnostic work up for unilateral vocal cord palsy. Contrast-enhanced CT revealed the left common carotid artery to be arising from the ascending part of a retrotracheal arch of aorta and traversing anterior to the trachea in the retromanubrial space.