Axillary Lymph Nodes

What are the six groups of axillary lymph nodes?

1. Lateral / Axillary vein group
2. Anterior / Pectoral / External mammary group
3. Posterior / Subscapular group
4. Central group
5. Apical / Subclavicular group
6. Interpectoral group

The lateral / axillary group course along the axillary vein towards the bicipital groove of the humerus.
The posterior / subscapular group follows the subscapular vein and is along the posterior axillary fold and the lateral border of the scapula.
The anterior / external mammary group follows the lateral thoracic vein and is beneath the anterior axillary fold.

The central group receives drainage from froups 1-3 and 6, then drains into the apical group. The apical group can later drain into the suprascapular nodes or into the subclavian trunk.

What are Rotter's nodes?

Nodes of the interpectoral group (between the pectoralis major and minor). These drain into both the apical and central groups.

What demarcates the three levels of axillary lymph node dissection?

Level 1 - lateral to the pectoralis minor
Level 2 - deep to the pectoralis minor
Level 3 - medial to the pectoralis minor

What lymph node groups comprise Level 1 nodes

Anterior / External mammary group
Lateral / Axillary vein group
Posterior / Subscapular group

What lymph node groups comprise Level 2 nodes?

Central node group
Possibly some apical nodes

What lymph node groups comprise Level 3 nodes?

Apical / Subclavicular node group

What surgeon is credited for recognizing that breast cancer can metastasize to internal mammary lymph nodes?

W. Sampson Handley, MS, FRCS

Where do internal mammary lymphatic trunks terminate?

Some drainage to Apical / Subclavicular nodal groups
The right side enters the right lymphatic duct
The left side enters the thoracic duct

What proportion of lymphatic flow from the breast enters axillary node groups?

>75%

What are routes of lymphatic drainage of the breast?

1. Laterally, primarily to the external mammary group (anterior)
2. Medially, to the internal mammary chain
3. Transpectorally, to interpectoral (Rotter's) nodes
4. Retropectorally, directly to apical/subclavicular nodes

Late... SG

Sources:
Mastery of Surgery, 5th ed.
Lachman's Case Studies in Anatomy, 4th ed.
O'Leary's Physiologic Basis of Surgery, 3rd ed.