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Axillary Lymph Node Dissection

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If you have a sentinel lymph node (SLN) biopsy and the results show that cancer may be present, your surgeon may recommend an axillary lymph node dissection.

This is the removal of all or a group of lymph nodes in the underarm (axilla). This will determine the exact number of lymph nodes that are affected, and is important to determine the stage of breast cancer and subsequent treatment plan.

The Three Levels of Axillary Lymph Node Dissection

The three levels of an axillary lymph node dissection, from least aggressive to most aggressive, are:

Level Description
Level I The surgical removal of all tissue below the lower edge of the pectoralis minor muscle.
Level II The surgical removal of the tissue lying underneath the pectoralis minor muscle.
Level III The most aggressive dissection and is the surgical removal of tissue lying above the pectoralis minor muscle.


A traditional axillary lymph node dissection usually includes removal of the nodes in levels I and II from the "fat pad" under the arm.