Variation in the course of the left phrenic nerve: a case report

Variations in the origin, course and distribution of the phrenic nerve have been reported previously. But in thisreport, a rare case of formation of an annulus was found in the course of the phrenic nerve near to its origin,during gross anatomy dissection of the left side of the neck of an Indian male cadaver. The annulus wasenclosing the origins of suprascapular and internal thoracic arteries. However, such variation was not found onthe opposite side of the same cadaver.