Neck dissection injury of a brachial plexus anatomical variant.

We describe an unusual brachial plexus anatomical variant that renders it vulnerable to injury in radical or modified neck dissection. It is represented by a looping redundant course of the most cephalad cervical division contribution to the brachial plexus. Unless recognized during development of the inferior surgical plane by blunt dissection techniques, injury to this portion of the brachial plexus may occur. An awareness of this infrequent variation in brachial plexus anatomy should be maintained.