The regional lymph node groups are the axillary nodes, supraclavicular nodes and the internal thoracic nodes.
Axillary Lymph Nodes
The axilla contains 5 groups of nodes - three peripheral groups, a central group and an apical group.
- The pectoral group lies on the posterior surface of the pectoralis major muscle. This group drains lymph from the breast, the anterior chest wall, and the upper part of the anterior abdominal wall.
- The subscapular group lies on the anterior surface of subscapularis, in close association with the subscapular vessels. This group drains lymph from the posterior chest wall and the inferior posterior neck
- The lateral group lies along the third part of the axillary artery and vein. It drains the lymph of the arm, with the exception of the skin of the shoulder which drains to infraclavicular nodes along the cephalic vein
- The central group lies beneath the pectoralis minor muscle, in close association with the axillary vessels. It drains lymph from the other three groups.
- The apical group lies in the apex of the axilla, medial to the medial border of the pectoralis muscle and in association with the first part of the axillary vessels. This group drains lymph from the entire upper limb, including the infraclavicular nodes.
Lymph from the apical group passes to the inferior deep cervical nodes, commonly referred to as supraclavicular nodes.
Supraclavicular Nodes (Inferior Deep Cervical Nodes)
The inferior deep cervical nodes lie in the neck, below the level of the cricoid cartilage. At this level they are closely associated with the internal jugular vein. In the inferior neck, nodes of this group lie between the subclavian and internal jugular veins, and drain lymph from the axillary nodes.
Internal Thoracic Nodes
These nodes lie along the internal thoracic vessels beneath the sternocostal joints. They are rarely involved in breast cancer but occasionally are a site of recurrence. Importantly, lymph vessels may pass to the abdomen from this group, although it is far more likely that lymph will pass superiorly to the brachiocephalic veins.