Absence of upper trunk of the brachial plexus

The brachial plexus is a complicated plexus supplying the upper limb. The brachial plexus is of great practical importance to the surgeon. It is encountered during operations upon the root of the neck, and hence it is in danger. Variations in the formation of the brachial plexus are common; and knowledge of the variation of the brachial plexus may be useful for surgeons, for improved guidance during supraclavicular block procedures, and for surgical approaches for brachial plexus. Here we report a case in which the superior trunk of the brachial plexus was found to be absent on the right side during a study on the cadaver-neck specimens in the Department of Anatomy.