Lateral Pectoral Nerve, Anterior View

Description

Running from the lateral cord of the brachial plexus, the lateral pectoral nerve (C5 to C7) courses anteriorly and medially across the axillary artery and vein toward the deep surface of pectoralis major. Proximally it lies inferior to the clavicle and anterior to the subclavius and clavipectoral fascia, then traverses or pierces the pectoral fascia near the thoracoacromial vessels. The nerve’s terminal branches spread within the pectoralis major, with potential communicating fibers to the medial pectoral nerve via the ansa pectoralis. Small structure, clear trajectory. That anterior relationship to the pectoralis minor region is the point. In deltopectoral and anterior axillary approaches, as well as during subpectoral breast implant placement and pectoralis major tendon repair, the lateral pectoral nerve is a named structure at risk; traction or division can weaken humeral adduction and internal rotation by denervating pectoralis major. The same anatomy helps explain anterior shoulder and chest wall pain patterns after brachial plexus injuries at the level of the cords, and it frames why selective motor blocks here can alter pectoral tone without affecting cutaneous sensation. Use this artwork to teach brachial plexus cord-level branching in gross anatomy and neuroanatomy courses, to annotate operative atlases covering deltopectoral exposure, mastectomy with reconstruction, or axillary node dissection, and to support CME material on iatrogenic pectoral nerve injury and postoperative chest wall dysfunction. Anatomical accuracy verified by SciePro's Medical Advisory Board.