An unusual case of axillary arch bridging across the anterior and posterior axillary folds in the distal part of axilla

Introduction Axillary arch is an additional muscle bundle of various dimensions extending from latissimus dorsi in the posterior fold of the axilla, to the pectoralis major in the anterior fold, to the short head of the biceps brachii or to the coracoid process [1, 2]. Ramsay, in 1795, described the axillary arch for the first time. He gave the description of a muscle bundle connecting pectoral muscle and latissimus dorsi [3]. However, the muscle has been named after Langer who gave the first description of the muscle in 1846 [4]. Incidence of axillary arch is stated to be present in 7% of subjects [5, 6]. MeridaVelasco et al. have reported 4 cases of axillary arch in their study of 64 upper limbs [7]. Various origin, course, insertion, nerve supply, dimensions; structure have been described by different authors. The axillary arch being reported in the present case is unique in its location, relationship with axillary neurovascular bundle and innervation.