Multiple unilateral variations in medial and lateral cords of brachial plexus and their branches.

During routine dissection of the upper extremity of an adult male cadaver, multiple variations in branches of medial and lateral cords of brachial plexus were encountered. Three unique findings were observed. First, intercordal neural communications between the lateral and medial cords were observed. Second, two lateral pectoral nerves and one medial pectoral nerve were seen to arise from the lateral and medial cord respectively. The musculocutaneous nerve did not pierce the coracobrachialis. Finally, the ulnar nerve arose by two roots from the medial cord. Knowledge of such variations is of interest to anatomists, radiologists, neurologists, anesthesiologists, and surgeons. The aim of our study is to provide additional information about abnormal brachial plexus and its clinical implications.