A common insertion of thoracoepicondylaris and an axillary arch of Langer: a case report

An axillary arch is considered to be an variant muscle or tendinous slip that arises form the lower border of latissimus dorsi to join the tendon of pectoralis major, coracobrachalis, or fascia over the biceps. It is present in about 7% of the cases and may be multiple [1]. An axillary arch is thought to be a vestige of panniculus carnosus muscle [2]. Thoracoepicondylaris is a very rare muscular variant which arises as an accessory slip from pectoralis major muscle, crosses the axilla and inserts onto the medial epicondyle of the humerus and medial brachial intermuscular septum [3]; according to Loukas et al., the term thoracoepicondylaris more accurately reflects the origin and insertion of the variant muscular slip. Many cases has been observed in the past about the occurrences of axillary arches, chondroepitrochlearis, dorsoepitrochlearis, costoepitrochlearis and costohumeralis but variations in relation to the common insertion of pectoralis major and latissimus dorsi muscle are rare and maybe important for diagnosis of unexpected and uncommon clinical conditions. It has been reported that such rare muscular slips may produce neurovascular complications as it arches over the axillary nerves and vessels [4]. Considering the frequency of procedures in this area, the knowledge of anatomical variation in the axilla is important for any surgical intervention [5].