Further tests for melanoma
This page tells you about further tests for melanoma skin cancer. There is information about
Further tests for melanoma
If you are found to have melanoma, your doctor will check how deep the melanoma is. If you have early stage melanoma that is only in the surface layers of the skin (stage 1A), the melanoma is very unlikely to have spread. You will not need to have further tests.
You may need further tests if your melanoma is more than 1mm deep into the skin (stage 1B or stage 2) or you have stage 3 or stage 4 melanoma.
Checking the lymph nodes
If your melanoma is more than 1mm deep (stage 1B or stage 2) your doctor may offer you further tests to check if the melanoma is in nearby lymph nodes. They may suggest a sentinel node biopsy. Or an ultrasound scan and sample of cells from the lymph nodes (biopsy).
During a sentinel node biopsy your doctor injects a dye close to the area of the melanoma and watches to find the first lymph nodes that the dye reaches. These are the sentinel nodes. Your doctor will remove the nodes and send them off to the lab. If they contain cancer cells, you will need another operation to remove the other lymph nodes in the area.
An ultrasound scan uses sound waves to look for changes in lymph glands. The doctor may take a sample of cells by putting a thin needle into the lymph node and drawing out some cells.
If you have stage 3 melanoma you will have a CT scan to see if the melanoma has spread any further. You may also have a CT scan if your melanoma is deeper than 4mm and you did not have a sentinel node biopsy. If the melanoma is found to have spread you may have other scans or blood tests.
After the tests
Your test results are bound to take a little time. You will probably feel very anxious while you wait. It may help to talk to a close friend or relative about how you feel. Or you may want to contact a cancer support group to talk to someone who has been through a similar experience.
You can view and print the quick guides for all the pages in the Diagnosing melanoma section.
If you are found to have melanoma, your doctor will check how deep the melanoma is. The depth of the melanoma in the skin affects how likely it is to come back and whether it may spread.
If you have early stage melanoma that is only in the surface layers of the skin (stage 1A), the melanoma is very unlikely to have spread anywhere else. You will not need to have further tests.
You may need further tests if
- Your melanoma is more than 1mm deep into the skin (stage 1B or stage 2)
- You have stage 3 or stage 4 melanoma
Read more about the stages of melanoma.
If the melanoma is more than 1mm deep into the skin (stage 1B or stage 2) or you have swollen lymph glands in the area, your doctor may talk to you about further tests. These are to see if there are any melanoma cells in nearby lymph glands. They may talk to you about the following tests
- A sentinel node biopsy
- An ultrasound scan and sample of cells from the lymph nodes (biopsy)
Sentinel node biopsy
Your doctor will talk to you about whether you want to have sentinel lymph node biopsy (SLNB). If you choose to have this test, you have it under general anaesthetic. It is a small operation that you have at the same time as the operation to remove the tissue around the melanoma (wide local excision).
A surgeon injects a small amount of dye or a mildly radioactive liquid into the area where the melanoma was removed. The dye or liquid drains away into the lymph glands. The surgeon can see when the dye reaches the first group of lymph nodes or they can measure the radioactivity with a scanner. These nodes are known as the sentinel nodes. The surgeon removes 1 or more of these nodes and sends them to the lab to see if they contain melanoma cells.
If the lab finds that none of the lymph nodes contain melanoma cells, you won't need to have any more nodes removed. And you usually won't need any further tests.
If the sentinel lymph nodes contain melanoma cells, there is a risk that other lymph nodes may also contain melanoma cells. Your doctor will usually offer you a further operation to remove the other lymph nodes in the area. This operation is called a lymphadenectomy.
At the moment, it is still unclear how useful a sentinel node biopsy is. The National Institute for Health and Care Excellence (NICE) has produced guidelines about the diagnosis and treatment of melanoma. They list some advantages and disadvantages of this test. You can talk to your doctor about sentinel node biopsy. They can help you decide whether or not to have this test.
Possible advantages of sentinel node biopsy are
- It can help doctors find out whether melanoma has spread to nearby lymph nodes so they can remove those lymph nodes
- It is better than an ultrasound scan at finding very small cancers
- Doctors can use the results to give you more information about what might happen to you in the future
- You may be able to take part in clinical trials looking at new treatments (you may not be able to take part in these trials if you haven’t had a sentinel node biopsy)
Possible disadvantages of sentinel node biopsy are
- It isn’t a cure for your melanoma and there is no good evidence that people who have sentinel node biopsy live longer than those who don’t have it
- The results don’t always predict what might happen to you in the future
- You need to have a general anaesthetic to have the operation
- The operation can cause health problems such as a collection of fluid under the wound or infection
Read more about the advantages and disadvantages of sentinel node biopsy in the Melanoma Assessment and Management guidelines on the NICE website.
There is a website that provides decision making tools called option grids. These grids provide information about different options, to help people make decisions about their treatment. You can look at the option grids website. You need to log in to use this website. You can find the option grids for sentinel node biopsy under 'M' for melanoma.
If you have melanoma cells in your lymph nodes, the doctor will change the stage of your melanoma to stage 3. They will offer you further tests to see if the melanoma has spread anywhere else.
Ultrasound scan and sample of cells
Sampling cells from the lymph nodes using ultrasound can show whether there are any melanoma cells in the lymph nodes. The ultrasound scan uses sound waves to look for changes in lymph glands. This involves putting some jelly on the skin over the lymph glands and passing a small device over the skin. The device sends out sound waves and receives them back. The sound waves bounce off the lymph glands and build up a picture on a screen.
The doctor may take a sample of cells by putting a thin needle into the lymph node and drawing out some of the cells. This is called fine needle aspiration (FNA). A pathologist then examines the cells in the laboratory.
Read more about the lymph glands. And read about having an ultrasound scan.
If you have stage 3 melanoma, your doctor will offer you a CT scan. If your melanoma is deeper than 4mm into the skin (stage 2C) and you have not had a sentinel node biopsy, you may also have a CT scan. This scan uses a series of X-rays to create a picture of the inside of the body. It can check whether the cancer has spread anywhere else.
Your doctor may also offer you an MRI scan or a PET-CT scan.
If you have stage 2C, stage 3 or stage 4 melanoma, the doctors may do genetic testing on your melanoma. This helps them make decisions about your treatment.
The doctor looks to see if the melanoma cells have changes (mutations) in certain genes, such as the BRAF V600 gene. About 40 to 50 out of every 100 people with melanoma skin cancers (40 - 50%) have this gene change. The change to the gene cause it to make an overactive BRAF protein. This makes cells grow and divide too fast.
If you have changes in the BRAF gene, doctors describe your melanoma as BRAF positive. If you don’t have changes, then your melanoma is BRAF negative.
Knowing whether you are BRAF positive helps your doctors decide which treatment is best for you. If you have stage 2C or stage 3 melanoma, this information is useful later on if your melanoma spreads further. If you have stage 4 melanoma that is BRAF positive, a type of biological therapy called a cancer growth blocker might help you.
Your doctor will ask you to go back to the hospital when your test results have come through. This is bound to take a little time. You will probably feel very anxious while you wait.
During this time it may help to talk to a close friend or relative about how you feel. Or you may want to contact a cancer support group to talk to someone who has been through a similar experience. There are organisations all round the UK that have trained counsellors who can give you support. Look at our melanoma organisations page for details of people you can contact if you have issues you want to talk over with someone trained to help you.
If you want to find people to share experiences with on line, you could use CancerChat, our online forum.
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