Supraclavicular Nerve of the Mammary Gland

Description

Arising from the superficial cervical plexus, the supraclavicular nerves (C3 to C4) descend inferiorly over the clavicle to supply the skin of the upper anterior thoracic wall, with their medial, intermediate, and lateral branches fanning out toward the superomedial breast and upper chest. Cutaneous twigs track superficially across the pectoral fascia, lying anterior to pectoralis major and approaching the superior pole of the mammary gland, where they overlap in territory with the anterior and lateral cutaneous branches of the intercostal nerves (T2 to T6). Within the breast parenchyma, lobules of adipose tissue and glandular units sit superficial to the pectoral musculature, converging via lactiferous ducts toward the nipple and areola. For sensory mapping, this view matters because patients often describe postoperative or posttraumatic dysesthesia in the upper breast and clavicular region, and supraclavicular nerve involvement is a common but under-taught contributor. Nerve injury or entrapment can occur with clavicle fracture fixation, central venous access, neck dissection, or surgical incisions along the clavicle, producing numbness, allodynia, or a painful neuroma that can be mistaken for intercostobrachial or intercostal nerve pain. The displayed terminal cutaneous distribution helps you separate supraclavicular territory from deeper mammary innervation and from the areolar supply typically dominated by T4. Educators can drop this plate into gross anatomy lectures on the cervical plexus, breast anatomy, and dermatomes, and surgical authors can pair it with discussions of infraclavicular approaches, mastectomy skin flap sensation, and postoperative neuropathic pain patterns. It also fits patient-facing counseling materials when explaining expected sensory changes after clavicular or breast procedures. Anatomical accuracy verified by SciePro's Medical Advisory Board.