Lymph node ultrasound and biopsy

A lymph node ultrasound and biopsy is a way of checking the lymph nodes under the arm (axilla). Sometimes the cancer cells can spread into the nearby lymph nodes.

Diagram showing the network of lymph nodes in and around the breast

A lymph node is part of the lymphatic system. This is a network of thin tubes (vessels) and nodes that carry a clear fluid called lymph around the body. This is an important part of the immune system. It plays a role in fighting infection and destroying old or abnormal cells.

Ultrasound scans use high frequency sound waves to create a picture of a part of the body. The ultrasound scanner has a microphone that gives off sound waves. The sound waves bounce off the organs inside your body, and are picked up by the microphone. The microphone links to a computer. This turns the sound waves into a picture.

If there are any areas that look abnormal, doctors can use the ultrasound to guide a needle and take a sample of cells.

Preparing for your lymph node ultrasound and biopsy

Check your appointment letter for exactly how to prepare for your test.

You doctor or nurse will explain what will happen and you sign a consent form. This is a good time to make sure you ask any questions that you have.

You are able to eat and drink normally beforehand. 

Take your medicines as normal. But if you are taking any blood thinning medicines you might need to stop them before the test. Your doctor or nurse will tell you when to stop.

What happens?

A nurse will ask you to change into a gown. They help you to lie down on the scanner couch and put your arm above your head.

The test takes about 10 to 15 minutes.

A specialist doctor called a radiologist does the scan. They put lubricating gel over your underarm area and hold an ultrasound probe on your skin. They move the probe over the skin.

You might feel a little pressure when they move the probe. It shouldn’t hurt. Tell them if it is uncomfortable for you.

Your doctor will take a sample of cells (biopsy) Open a glossary item if they see any changes in the lymph nodes on the ultrasound. They clean your skin and inject some local anaesthetic using a fine needle. This might sting for a short time. When the area is numb they put a thin, hollow needle attached to a syringe through your skin and draw back some cells and fluid into the syringe. They might take samples from more than one area.

Your doctor will not take a biopsy if the lymph nodes appear normal.

They send the samples to a laboratory for tests.

After the lymph node ultrasound and biopsy

You should be able to go home soon afterwards.

You will have a small dressing over the biopsy area. Your doctor or nurse will tell you how to look after this for the next few days.

Getting your results

You should get your results within 1 or 2 weeks at a follow up appointment. 

Waiting for test results can be a very worrying time. You might have contact details for a specialist nurse who you can contact for information if you need to. It can help to talk to a close friend or relative about how you feel.

You can also contact the Cancer Research UK nurses on freephone 0808 800 4040 for information and support. The lines are open from 9am to 5pm, Monday to Friday.

Contact the doctor who arranged the test if you haven’t heard anything after a couple of weeks.

What will happen following my results?

If your result show that your breast cancer is in the lymph nodes, this may mean that you will need surgery to remove all or most of the lymph nodes in your armpit. You have this at the same time as your breast surgery, or as a second operation. This is called an axillary lymph node dissection or clearance.

If the lymph nodes look normal, you may have a sentinel lymph node biopsy during your breast surgery. This is to make sure that cancer has not spread to the nearby lymph nodes. The sentinel node is the first node that fluid drains to from the breast into the armpit.

Your doctor will explain the results to you and tell you what type of treatment you need. 

Possible risks

A lymph node biopsy is a very safe procedure but your nurse will tell you who to contact if you have any problems after your test. Your doctors will make sure the benefits of having a lymph node biopsy outweigh these possible risks.


You might see a small amount of blood on the dressing after the biopsy. Let your doctor or nurse know straight away if there is a lot of bleeding from your biopsy site.


Contact your GP or the hospital if you have a high temperature or feel unwell or if there is swelling at the biopsy site.

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