The armpit
Twenty to thirty nodes lie in the fat of the armpit, around the axillary vein and artery and under the pectoralis major. They drain the arm, the wall of the chest and the upper back, and they receive about three quarters of the lymph of the breast.
The superficial lymph vessels of the arm running up to the axillary nodes, with the supratrochlear node above the elbow, Gray's Anatomy, 1918, figure 606Wikimedia Commons, Henry Vandyke Carter, Public domain (Gray606.png)
A cancer of the breast spreads first to these nodes. To check them, a surgeon injects a dye or a tracer near the tumour and removes the first node it reaches, the sentinel node. If that node is clear, the others are very likely clear too and can stay.
The lymph vessels of the breast and the groups of axillary nodes, semidiagrammatic, Gray's Anatomy, 1918, figure 607Wikimedia Commons, Henry Vandyke Carter, Public domain (Gray607.png)
Sources
- Susan Standring (ed.), Gray's Anatomy, 42nd ed. (2020), chapters on the shoulder girdle and arm and on the chest wall and breast.
- Henry Gray, Anatomy of the Human Body, 20th ed. (1918), section VIII, The Lymphatics of the Upper Extremity.
Prev: The neckNext: The groin