This test uses high frequency sound waves to look at your lymph nodes. Your doctor might take a sample (biopsy) from the lymph node if it looks abnormal.
You might have this test to find out if melanoma skin cancer has spread from the skin to the lymph nodes.
What is a lymph node?
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.
The nodes are bean shaped structures that filter the lymph fluid and trap bacteria and viruses, and cancer cells.
What is an ultrasound?
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 again by the microphone. The microphone links to a computer. This turns the sound waves into a picture.
If the lymph nodes look abnormal, doctors (radiologists) use the ultrasound to guide them to take samples of cells or tissue. They do this using a thin needle. You might hear this called a fine needle aspiration.
A specialist doctor (pathologist) looks at the samples under a microscope to see if there are any cancer cells.
Where you have your test
You normally have this as an outpatient in the imaging department of the hospital. You have the test under local anaesthetic. This means you are awake, but you have an injection to make sure the area is numb.
Preparing for the test
Check your appointment letter for exactly how to prepare. You sign a consent form before the test. This is a good time to ask the doctor any questions that you have.
You should be able to eat and drink normally before the test.
Take your medicines as normal unless you're told otherwise. If you're taking medicines to thin your blood, your doctor might ask you to stop them beforehand.
Before the test
When you arrive at the department, a nurse will ask you to change into a gown. Then they show you to the test room.
During the test
You'll have the test lying down on the couch.
The doctor or a sonographer puts a cold lubricating gel on the skin by the lymph nodes. A sonographer is a trained professional who specialises in ultrasound scanning.
They put a handheld ultrasound probe on your skin. The gel helps the probe to move over your skin. You may feel a little pressure when they move the probe over your skin. Tell them if it is uncomfortable. It shouldn’t hurt.
This will be the end of your test if your lymph nodes look normal. But your doctor will want to take a sample of tissue (biopsy) if anything looks abnormal.
Your doctor cleans your skin and then numbs the area with local anaesthetic. They put a fine needle through your skin and draw back some cells and fluid into a syringe. Or they take out some tissue through a needle. They send the samples to a laboratory. A specialist doctor (pathologist) looks at the biopsy under a microscope.
The biopsy takes about 15 to 20 minutes.
After the lymph node ultrasound and biopsy
You usually go home the same day as your biopsy.
You have a small dressing over the biopsy site. Ask your doctor how best to look after this for the next few days.
A lymph node biopsy is a safe procedure but your doctor or nurse will tell you who to contact if you have any problems after your test. Your doctors make sure the benefits of having a lymph node biopsy outweigh any possible risks.
You might have some mild pain or discomfort around the site. Taking a painkiller such as paracetamol can help.
There is a small risk of bleeding. Your doctor can normally control this by pressing on the area. If there is a lot of blood from the biopsy site, let your doctor know straight away or go to your nearest accident and emergency department (A&E).
Contact your GP or the hospital if you have a high temperature or feel unwell. Or if there is redness, swelling or fluid (discharge) at the biopsy site.
Getting your results
It takes 1 or 2 weeks to get the results. Your specialist will usually discuss them with you at your next clinic appointment.
Waiting for test results can be a worrying time. You might have contact details for a specialist nurse. You can get in touch with them for information and support if you need to. It may help to talk to a close friend or relative about how you feel.