Surgery - Lymph Node Dissection

Reviewed by: HU Medical Review Board | Last reviewed: June 2023

Lymph node dissection is a surgical procedure in which several lymph nodes are removed from the underarm. This is also called an axillary lymph node dissection. The nodes are examined under a microscope to see if the breast cancer has spread into them.

How does lymph node dissection help diagnose breast cancer?

Lymph nodes are an important part of the immune system. They filter the lymph fluid. This is a clear-to-white fluid that helps nourish tissues. It also helps remove damaged cells (including cancer cells), bacteria, and viruses from the tissues.1,2

Lymph nodes contain many white blood cells, including special white blood cells called lymphocytes and macrophages. These are key parts of the immune system that help the body fight off infection and remove damaged cells, like cancer cells.1,2

When cancer mutates, it is often able to hide from the immune system. This means the body's natural defenses do not recognize the cancer, allowing it to grow and spread. When breast cancer spreads, it often first spreads to the axillary lymph nodes. Lymph node dissection allows doctors to understand the extent of your cancer to guide treatment decisions.1,2

The sentinel lymph node

The sentinel lymph node is the first lymph node in the chain of lymph nodes that drain the lymph fluid from the breast. In sentinel lymph node biopsy, only the first 1 to several lymph nodes are removed. To identify which lymph node(s) are sentinel, a radioactive substance or dye is injected into the breast near the tumor. This dye drains to the sentinel node, making it visible for the surgeon to identify. If there is no cancer found in the sentinel node(s), it is generally unlikely that there will be cancer in the other axillary lymph nodes.3,4

What are the possible side effects of lymph node dissection?

Short-term side effects of surgery to the lymph nodes may include:1

  • Pain
  • Swelling
  • Bleeding
  • Risk of infection

Surgery to the underarm area may also cause stiffness or numbness. This may limit arm movement.1

Surgery to the lymph nodes may also cause long-term side effects. Both sentinel lymph node biopsy and axillary lymph node dissection increase the risk of developing lymphedema. This is an irregular swelling in the arm or chest. When there are fewer lymph nodes to do the job of draining the lymph fluid, this swelling can occur due to a cut on the arm or hand, infection, or trauma to the arm.1,3

The risk of lymphedema increases with the number of lymph nodes removed. This means the risk of lymphedema is generally less with sentinel lymph node biopsy than with axillary lymph node dissection. There are ways to treat lymphedema. Any signs of swelling should be immediately reported to a doctor.1,3

These are not all the possible side effects of lymph node dissection. Talk to your doctor about what to expect or if you experience any changes that concern you following lymph node dissection.

Things to know about lymph node dissection

The surgery to test the axillary lymph nodes for cancer usually takes about an hour. However, the time to be admitted varies by location. In certain cases, the lymph node biopsy is done at the same time as breast surgery, such as a lumpectomy or mastectomy. The surgery is done using general anesthesia.5

Once the lymph nodes have been removed, they are sent to a lab to be examined under a microscope. It can take several days to get the pathology report.5

Recovery time after surgery varies. To help you recover and reduce side effects, your doctor may recommend physical therapy exercises. These can help restore range of motion and strength in the affected arm.5

By providing your email address, you are agreeing to our privacy policy.