Stage 2 is when the melanoma is more than 2mm thick, or more than 1mm thick and ulcerated (the skin is broken). Stage 3 is where melanoma cells are found in one or more lymph nodes.

After diagnosis and initial treatment you may have further tests to check if the cancer has spread to the lymph nodes and further treatment to try to reduce the risk of the melanoma coming back.

The lymph nodes are part of the lymphatic system, which is part of the body's natural defence against infection. The lymph nodes (sometimes called glands) are situated throughout the body and are connected by very fine lymphatic vessels. Fluid drains from the tissues into the lymphatic system.

Sometimes melanoma cells can travel to the lymph nodes. If you have melanoma, your doctor may suggest further tests to see if it has spread.

Fine needle aspiration (FNA)

Your doctor may suggest this if you have a swollen lymph node. The doctor uses a fine needle and syringe to take some cells from the swollen node. These are then examined in the laboratory.

Sentinel node biopsy

Your surgeon may suggest that during or after your operation you have a sentinel node biopsy to see if the melanoma cells have spread to the lymph nodes. The sentinel node is the one closest to the melanoma. To identify the sentinel node, two substances are injected into the area – one is mildly radioactive and the other is coloured blue. The surgeon removes the node which has taken up these liquids (the sentinel node), so it can be tested to see whether it contains melanoma cells.

The risk of problems following the sentinel node biopsy is very low. They include infection or having some fluid collect in the area. These can easily be treated.

Sentinel node biopsy is still being researched in trials, to see how effective it is.

If you have a sentinel node biopsy, you may not need to have any other lymph nodes removed. If melanoma cells are found in the sentinel node, your doctor will suggest another operation (lymph node dissection) to remove more of the lymph nodes in the area.

Lymph node dissection

This is an operation to remove all the lymph nodes in the area. It is sometimes called a block dissection and is done under a general anaesthetic. You will have some soreness for a few weeks after the operation, but hopefully it should not stop you doing any of your normal activities. Your doctor or nurse will give you detailed advice about what you can or can’t do. Sometimes, the removal of lymph nodes may cause a gradual swelling in the limb where the glands were removed. This is called lymphoedema.

The following tests may be done either before or after you have a lymph node dissection.

Blood tests

To check your general health.

Chest x-ray

To check your general health and look for any signs of melanoma in the lungs.

Liver and abdominal ultrasound scan

This uses sound waves to make up a picture of a particular area of the body. Once you are lying comfortably on your back, a gel is spread on your abdomen. A small device like a microphone is then passed over the area. The echoes are converted into a picture by a computer.

CT scan (computerised tomography scan)

A series of x-rays is taken of the chest and abdomen. These are fed into a computer to build up a detailed picture of the body's organs and may show whether the melanoma has spread. The scan takes from 10 to 30 minutes. You may be given a drink or injection of a dye which allows particular areas to be seen more clearly. For a few minutes this may make you feel hot all over. If you are allergic to iodine or have asthma you could have a more serious reaction to the injection, so it is important to let your doctor know beforehand. You will probably be able to go home as soon as the scan is over. Your doctor may also want you to have a CT scan of your brain.

Treatment is sometimes used after surgery to try to reduce the risk of the melanoma coming back. This is called adjuvant treatment. At the moment, there is no standard adjuvant treatment for stage 2 or 3 melanoma, although treatment with a drug called interferon is sometimes suggested.

Interferon is a substance produced by the body to fight viral infections such as flu. A man-made version is available. The aim is that interferon will help stimulate the body’s own immune system to fight the melanoma. Interferon is given as an injection just under the skin (subcutaneously) usually three times a week. Interferon can cause side effects similar to flu symptoms (fever, chills, headache, tiredness). Although these can be troublesome, they gradually disappear once the treatment is over.