How advanced melanoma is diagnosed
If you’ve previously been treated for a melanoma, you’ll probably be attending a clinic for check-ups.
Your specialist or GP may have arranged tests to investigate your new symptoms. The test(s) your doctor arranges will depend on your particular symptoms.
Some people who are newly diagnosed with a primary melanoma will have further tests to check whether the cancer cells have spread to the lymph nodes nearby or to other parts of the body. The most common place for melanoma cells to spread to is the lymph nodes closest to the original melanoma.
If these tests are positive or if you have symptoms that suggest the melanoma has spread elsewhere, you may have some of the following tests:
Blood samples will be taken to check your general health and how well organs such as your liver and kidneys are working.
You may have a chest x-ray to check whether the cancer has spread to your lungs.
CT (computerised tomography) scan
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A CT scan takes a series of x-rays, which build up a three dimensional picture of the inside of the body. It can be used to find out whether the melanoma has spread to other parts of the body.
The scan takes 10–30 minutes and is painless. It uses a small amount of radiation, which is very unlikely to harm you and will not harm anyone you come into contact with. You will be asked not to eat or drink for at least four hours before the scan.
You may be given a drink or injection of a dye, which allows particular areas to be seen more clearly. This may make you feel hot all over for a few minutes. It’s important to let your doctor know if you are allergic to iodine or have asthma, because you could have a more serious reaction to the injection.
You’ll probably be able to go home as soon as the scan is over.
MRI (magnetic resonance imaging) scan
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This test uses magnetism to build up a detailed picture of areas of your body. Like a CT scan, an MRI scan can be used to find out whether melanoma has spread to other parts of the body.
The scanner is a powerful magnet, so you may be asked to complete and sign a checklist to make sure it’s safe for you. The checklist asks about any metal implants you may have, such as a pacemaker, surgical clips or bone pins. You should also tell your doctor if you’ve ever worked with metal or in the metal industry, because very tiny fragments of metal can sometimes lodge in the body. If you do have any metal in your body, it’s likely that you won’t be able to have an MRI scan. In this situation, another type of scan can be used.
Before the scan, you’ll be asked to remove any metal belongings, including jewellery. Some people are given an injection of dye into a vein in the arm, which doesn’t usually cause discomfort. This is called a contrast medium and can help the images from the scan to show up more clearly. During the test you’ll lie very still on a couch inside a long cylinder (tube) for about 30 minutes. It’s painless but can be slightly uncomfortable, and some people feel a bit claustrophobic. It’s also noisy, but you’ll be given earplugs or headphones. You can hear and speak to the person operating the scanner.
Ultrasound scans use sound waves to build up a picture of part of the inside of the body, such as the abdomen, liver or pelvis.
If you have a pelvic ultrasound, you’ll be asked to drink plenty of fluids so that your bladder is full. This helps to give a clearer picture. An ultrasound specialist will then spread a gel onto your abdomen and gently rub a small microphone-like device, which produces sound waves, over the area. The sound waves are converted into a picture by a computer. An ultrasound scan is painless and only takes a few minutes.
A bone scan can show up any abnormal areas of bone. If you have symptoms, it may be done to find out if the melanoma has spread to the bones.
A very small amount of a mildly radioactive substance is injected into a vein, usually in your arm, and travels around the body and bloodstream. Abnormal areas of bone absorb more radioactivity than normal bone and show up on a scanner.
You’ll have to wait for up to three hours after having the injection before you have a scan. This is to allow time for the bone to absorb the radioactive substance. It’s a good idea to take a book or a magazine with you to help pass the time. After a few hours you’ll have a scan of the whole body.
Bone scans can’t always tell whether an abnormal area is due to cancer or other conditions, such as arthritis. Sometimes more detailed scans, such as CT or MRI scans, will also be needed.
PET (positron emission tomography) scan
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A PET scan uses low-dose radioactive glucose (a type of sugar) to measure the activity of cells in different parts of the body. It may help to find out whether a tumour is growing and whether it is cancerous (malignant) or non-cancerous (benign).
A very small amount of a mildly radioactive substance is injected into a vein, usually in your arm. A scan is then taken a couple of hours later. Cancer cells are usually more active than surrounding tissue, and show up on the scan. Not all hospitals have PET scanners, so if you need one you may have to travel to another hospital.
Waiting for test results
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It may take up to two weeks for the results of your tests to be ready, and a follow-up appointment will be made for you. This waiting period can often be a very anxious time and it may help you to talk things over with a relative, close friend, your specialist nurse at the hospital or another support organisation.
You can also contact Macmillan for support.