Introduction: Langer’s axillary arch is a muscular slip extending from the anterior border of latissimus dorsi muscle to tendons, muscles or fascia around the superior part of humerus, lying anterior to the neurovascular bundle. It is the best-known anatomic variant of the axilla, with definite clinical and surgical implications.
Case Report: A 55-year-old female presented with a 3x3 cm carcinoma in the superomedial quadrant of the right breast, with no palpable regional lymph nodes. She underwent breast conservation surgery with axillary nodal clearance. During axillary dissection, an unusual muscle slip was identified crossing the axilla, connecting the anterior border of latissimus dorsi to the posterior surface of pectoralis major, anterior to the axillary artery, vein and brachial plexus.
Conclusion: Preoperative knowledge is essential to identify such unusual anatomy and to appropriately tackle it to avoid surgical complications and adequate axillary lymph node clearance.

Keywords: Axillary arch, Axillary lymph node dissection, Breast carcinoma