Sentinel lymph node biopsy

What are Lymph Nodes?

Lymph nodes are small organs that are best thought of as filters trapping bacteria and cancer cells. They are present in most areas of the body but particularly the armpits, groins, neck, abdomen and chest.

What is the Sentinel Node (SN)?

The sentinel lymph nodes (glands) are the first lymph nodes in your armpit to which breast cancer can spread.

What is Sentinel Node Biopsy (SNB)?

Images by PD Dr. med. G. Berclaz

By removing the sentinel lymph nodes we can find out whether the breast cancer has or has not spread to the other lymph nodes in the armpit.

This important information helps us to advise you about the stage of your cancer and the best type of breast cancer treatment for you.

Recent studies have shown that removal of the sentinel lymph nodes is just as safe and accurate as traditional armpit surgery that removes more nodes.

Side effects of armpit surgery

For some patients, armpit node removal can cause temporary shoulder stiffness, nerve pain and/or permanent swelling of the arm (lymphoedema). The side effects of armpit surgery increase with the number of lymph nodes removed. This means if we remove only the SNs side effects are less than traditional armpit surgery where more nodes are removed. Usually 1-3 sentinel nodes are removed.

Finding the Sentinel Lymph Nodes

Images by PD Dr. med. G. Berclaz

Before surgery a small amount of radioactive fluid will be injected into your breast. This fluid travels to the SNs. You may also have a scan to mark the position of the SNs.

During your surgery a blue dye will be injected into the skin of the breast. This also travels to the SNs. The surgeon using a special radiation detection probe can then find the SNs that are radioactive and/or blue.

What if we cannot find the Sentinel Nodes?

Occasionally it is not possible to find the SNs. If this happens, but only with your permission, the surgeon, during the same operation will remove four lymph nodes to make sure the nodes which are likely to be the SNs are removed.

What if the SN looks cancerous at surgery?

Occasionally at the time of surgery it can be obvious the lymph nodes are cancerous. Only with your permission the surgeon may proceed to remove as many nodes as necessary. This will save you a second armpit operation a few weeks later. This is not common.

After Surgery

The pathologist examines the SNs under the microscope - this takes a week. If the SNs contain cancer cells it is possible further cancerous nodes are still present in the armpit (about half the time). For this reason you will require either further armpit surgery to remove as many of the remaining lymph nodes as possible or you may be offered radiotherapy to the armpit.

What are the benefits of SNB?

• Less discomfort and more early mobility in the shoulder/arm
• Less risk of arm swelling (lymphoedema)
• No drains
• Shorter hospital stay and quicker overall recovery

What are the disadvantages of SNB?

• Blue dye will discolor urine, faeces, tears & contact lenses (please remove before surgery) for a few days. Most patients appear pale and unwell because of the dye – do not be alarmed! The breast skin will be discolored for a few months and occasionally a year or so.
• Allergic reaction to the blue dye can rarely occur whilst under the anaesthetic. This can be treated but can (very rarely) be severe.
• Injection of radioactivity into the breast may cause slight discomfort.
• If the pathologist finds the sentinel lymph nodes contain cancer, you will need more armpit treatment. This may require a second armpit operation.
• There is a small risk (less than 5%) that the procedure doesn’t identify the correct lymph nodes. In this case it is possible that a lymph node containing cancerous cells could be left behind. The surgeon can inform you of your individual risk of this.

Before the operation you will need to sign consent form

• To have Sentinel lymph node biopsy using radioactive fluid and blue dye.
• If the surgeon cannot find the SN or the glands look cancerous we need your permission to remove more nodes, whilst under the same anaesthetic. If you do not want this to happen you must tell us beforehand.