Lymph node surgery for breast cancer

Woman looking at her underarm in the mirror

If breast cancer spreads, the first place it spreads to is the lymph nodes in your armpit.

These lymph nodes (diagram: small green balls) will be checked for any signs of cancer, either before or during your breast cancer surgery.

(Image courtesy of CRUK / Wikimedia commmons)

Checking the lymph nodes for cancer

Before surgery – Lymph node ultrasound scan and biopsy

You will have an ultrasound scan of the lymph nodes in your armpit area. If they look abnormal, a sample of the cells will be taken to see if they contain cancer. If they do, your surgeon will remove the nodes during your breast cancer surgery. This is called axillary lymph node dissection (ALND) or axillary clearance. 

During surgery – Sentinel lymph node biopsy

If the ultrasound scan doesn’t show any signs of cancer in your lymph nodes, your surgeon will check them during the operation to remove the tumour from your breast. This is called a sentinel lymph node biopsy

How is a sentinel lymph node biopsy done? 
  • You will have a mildly radioactive liquid (called a ‘tracer’) injected into your breast close to the tumour. This is usually done a few hours before the operation. 
  • The tracer will travel to the lymph nodes. The first lymph node to receive the tracer is called the sentinel node. This node and maybe 1-2 others will be removed and tested for cancer. It usually takes about a week to get the results. 
Sentinel lymph biopsy results
  • If the lymph nodes are clear of cancer cells: You shouldn’t need to have any more lymph nodes removed
  • If the lymph nodes contain cancer cells: You will probably need more surgery to remove some more or all of the lymph nodes in your armpit. This usually happens about 2 weeks after getting the results. Or you may have radiotherapy to destroy the cancer cells instead. 

Surgery to remove lymph nodes (axillary clearance)

If the doctors have found cancer in your lymph nodes, some more nodes will be removed. In some cases, most of the lymph nodes in your armpit will need to be removed. This is called an axillary clearance. 

After surgery to remove your lymph nodes, a drain (tube) will be put in to take away lymph and other fluids for a few days. The drain will be removed when the amount of fluid flowing out has reduced. 

For most people, this operation can be done without causing serious difficulty with shoulder movement, or arm swelling. A physiotherapist at the hospital will show you special arm exercises to help you recover.

Side-effects of removing lymph nodes

Soreness or numbness

The area under your arm will feel numb or sore for a while and you may experience some tingling or pins and needles. Taking painkillers regularly can help with any discomfort. 

Scar tissue in the armpit (cording)

Some women get a feeling like there is a tight rope or cord running from their armpit down their arm towards the hand after this surgery. This is called cording or banding. It can also be called axillary web syndrome. Cording can develop weeks or months after surgery. 

Cording can be painful or it might make it difficult to move your arm. It usually gets better on its own after a few months, but tell your nurse if you have cording.

They can refer you to a physiotherapist or teach you exercises to help. Anti-inflammatory painkillers or massage may also help. Ask at the hospital if they can recommend a massage therapist. 


There is a small risk of swelling in your arm (lymphoedema). This can happen any time after the operation. If you notice any swelling in your arm, let your doctor know. Lymphoedema is easier to manage if it’s treated early. Read more about lymphoedema and how to manage it.

For more information

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