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Lymph node ultrasound and biopsy

Find out what a lymph node ultrasound and biopsy is, how you have it, and what happens afterwards.

What it is

A lymph node ultrasound and biopsy is a way of checking the lymph nodes under the arm after breast cancer is diagnosed. Sometimes the cancer cells can spread into the nearby lymph nodes.

Diagram showing the network of lymph nodes in around the breast

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 above your head.

The test takes about 10 to 15 minutes.

A sonographer does the scan. They put a cold 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.

If the ultrasound shows changes in the lymph nodes, your doctor will take a sample of cells from the area. 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 through your skin and draw back some cells and fluid into a syringe. They might take samples from more than one area.

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.

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.

Information and help

Dangoor sponsorship

About Cancer generously supported by Dangoor Education since 2010.