Variant innervation of the coracobrachialis muscle and unusual course of the musculocutaneous nerve in man.

During the educational gross anatomy dissections of the upper extremities of 60 embalmed cadavers in our laboratory, the coracobrachialis muscle was found to be innervated by a nerve branch arising from the lateral root of the median nerve, but not from the musculocutaneous nerve nor from the lateral cord of the brachial plexus. Also the musculocutaneous nerve was found not to pierce the coracobrachialis muscle and to course downwards medial to it. The combination of two variations was seen in the right arm of a 64-year-old Turkish female cadaver. No other abnormality was observed in the branching pattern of the brachial plexus on both sides.