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School of Medicine
Axillary Node Dissection
Lymph nodes serve as a filtering system for the lymphatic system (a system of vessels that collects fluids from cells for filtration and re-entry into the blood). The first nodes in the armpit area (axilla) that are affected by breast cancer are also called the sentinel, or guardian, lymph nodes. Learn more about sentinel lymph node biopsy.
If the cancer is found to have spread to the sentinel lymph nodes or other nodes in the axillary area, then your breast surgeon may recommend an axillary lymph node dissection. If only one or two sentinel lymph nodes contain evidence of cancer, then an axillary lymph node dissection may not be necessary. If three or more sentinel lymph nodes are found to contain cancer, then an axillary lymph node dissection will most likely be recommended. An axillary lymph node dissection is also indicated if it is known prior to surgery (via fine needle aspiration biopsy or core needle biopsy of an enlarged or abnormal lymph node) that the cancer has spread to the lymph nodes in the axilla.
There are three levels of axillary lymph nodes and options for dissection:
- Level I – This refers to removal of all tissue below the axillary vein and extending to the side where the axillary vein crosses the tendon of a muscle called the latissimus dorsi.
- Level II – This includes lymph nodes located under one of the chest wall muscles called the pectoralis minor.
- Level III – This is the most aggressive dissection and removes all of the nodal tissue from the axilla.
Each woman has a different number of lymph nodes in her body, so the decision about how many nodes to remove is not based on number, but on location.
In most cases, level I and II lymph nodes would be removed if an axillary lymph node dissection is indicated.