The axillary arch compressing the brachial plexus

Abstract

The axillary arch is a variant slip extending between the latissimus dorsi muscle and the pectoralis major. During educational dissection, a variant muscle was founded in left arm of 70-year-old female cadaver. A slip muscle originated from the lateral border of the latissimus dorsi and crossed the axilla obliquely. Therefore, we defined this muscular variation as axillary arch. It ran anterior (superficial) to the medial and lateral cords of the brachial plexus, and then it inserted to the tendon part of the pectoralis minor muscle. We reported this variant muscle and discussed its clinical and embryological significances.