Diagnosing melanoma

Tuesday 30 June, 2009

Reviewed: Prof. John Kelly, Dermatologist;
Mr David Speakman, Head, Melanoma and Skin Service, Peter Mac

On this page: Symptoms | Health professionals you may see | How melanoma is diagnosed | Biopsy | Staging the melanoma | Other tests | Lymph node biopsy and dissection | Melanoma centres

Symptoms

The first sign of a melanoma is usually a new spot or a change in an existing freckle or mole. The change may be in size, shape and/or colour. The change is normally noticed over several weeks or months rather than days.

A normal freckle or mole is usually small and has an even colour and a smooth edge. A melanoma often has an irregular edge or surface. It may be spotted with brown, black, blue, red, white and/or light grey. A freckle or mole that itches or bleeds is sometimes (but not always) a melanoma. A freckle or mole that becomes larger or irregular in shape may be a melanoma.

It's quite normal for new moles to appear and change during childhood and pregnancy. However, in adults a new mole is less common and could be a melanoma.

Melanoma can occur anywhere on the body.

Doctors and other health professionals you may see

Your doctor will examine you and refer you for tests to see if you have cancer. This can be a worrying and tiring time, especially if you need to have several tests.

If the tests show you have or may have cancer, your doctor will refer you to a specialist, who will examine you and may ask you to have more tests. If you have cancer, one or more specialists will advise you about treatment options.

You may be cared for by a team of health professionals from the relevant major fields (see below). Ideally, all your tests and treatment should be available at your hospital; however, this may not be possible.

Specialists and other health professionals who care for peo-ple with melanoma include:

  • dermatologists, who specialise in the diagnosis and treatment of skin disorders
  • histopathologists, who examine tissue to diagnose cancer
  • surgeons, who specialise in operations to remove melanoma. You may see a plastic surgeon, who specialises in surgery to reconstruct damaged parts of the body. Plastic surgeons often are used when a better cosmetic result from a scar is needed.
  • medical oncologists, who specialise in chemotherapy and other aspects of cancer care
  • radiation oncologists, who specialise in radiotherapy
  • nurses and general practitioners, who will help you through all stages of your cancer
  • dietitians, who will recommend the best diets to follow during and after treatment
  • social workers, psychologists, physiotherapists, counsellors and occupational therapists, who will advise you on support services available and help you get back to normal activities.

How melanoma is diagnosed

Melanoma is diagnosed by physical examination and biopsy. Your doctor will first examine the suspicious spot or mole and other spots and moles and ask about your own and your family's history of melanoma. Your doctor may use a magnifying instrument, called a dermoscope, to examine the spot, to improve the chances of making a correct diagnosis. The doctor may also feel the lymph nodes near the suspicious spot or mole.

Biopsy

If your doctor suspects that you have melanoma, they will suggest that you have a biopsy.

This is a quick and simple procedure. Your family doctor or general practitioner may do it. Or you may be referred to a dermatologist or surgeon. You will have a local anaesthetic. The doctor will use a scalpel to remove the spot and some tissue around it. You will have a stitch or stitches to help the wound to heal.

The tissue that is cut out will be sent to a laboratory to be examined under a microscope. It will probably take around a week for the results of your tests to be ready, and a follow-up appointment may be arranged. This waiting period can be an anxious time. It may help to talk things over with a close friend or relative.

If the cells are found to be cancerous, the doctor will stage the melanoma. They may also do other tests to see if the cancer cells have spread. This may include taking more tissue.

Staging the melanoma

If the biopsied tissue is found to have cancer cells in it, the doctor will measure the depth to which the cancer cells go. This is called ‘staging' the disease. The deeper the cancer cells are in the skin, the more likely it is that the cancer could have spread. If the cells are not very deep in the skin, removing the melanoma may be all that will be needed, and you will not require any further treatment.

The staging system used for melanoma is known as the ‘TNM system' (T = tumour, N = lymph nodes, M = metastases).

  • T followed by a number between 1 and 4 describes how far the melanoma has invaded the skin. A higher number after the T (for example T3 or T4) means it has spread beyond the epidermis and into the dermis.
  • N plus a number from 0 to 2 describes whether the cancer has spread to the lymph nodes. Higher numbers are used when more than one group of nodes are affected by the cancer.
  • M followed by 1 shows that the cancer has spread to other organs or lymph nodes in the body. M0 cancers have not spread in this way. 

Doctors combine this information to determine the stage of the cancer, from Stage 1 to Stage 4. For example, a cancer as-sessed as T1, N0, M0 (tumour contained within the dermis, lymph nodes not affected and no metastasis) would be called Stage 1 cancer.

You might hear the term ‘level' or ‘Clark level'. This is an assessment of the layers of skin involved. It is not the same as the stage of the melanoma.

Ask your doctor to explain the stage of your cancer in a way you can understand. This may help you choose the best treat-ment for your own situation.

Other tests

If you have melanoma, your doctor may recommend other tests. This is generally if surgery is being planned or if there is evidence that the melanoma may have spread to other parts of the body. The tests include:

Lymph node biopsy and dissection

If there is suspicion that the melanoma might have spread to your lymph nodes, your doctor may recommend that you have a fine needle aspiration biopsy or a sentinel node biopsy.

In a fine needle aspiration biopsy, the doctor inserts a needle into the node suspected of being affected by cancer and draws tissue into the syringe. This tissue is then examined under a microscope to see if it contains cancer cells. Occasionally, a node is removed surgically (‘open biopsy') so that the tissue can be examined.

If cancer cells are found in the node/s, the nodes may be surgically removed (‘dissected').

A sentinel node biopsy locates the lymph nodes that drain fluid from the area where the melanoma developed. A small amount of radioactive fluid and blue dye is injected into the skin around the melanoma. The radioactive fluid will not cause you any harm. After about an hour, the surgeon will pass a hand-held machine called a ‘counter' over the area. This shows which node the injected fluid has gone into first: this is the sentinel node. In a small operation, the sentinel node will be removed and checked for cancer cells.

If cancer cells are found, surrounding nodes may also be removed. This is to try to stop cancer coming back in the same area.

Sentinel lymph node biopsy does not increase the chances of cure. In appropriate cases it can provide more information about the spread of melanoma and its severity and assist your doctor in further planning your treatment. 

Melanoma centres

Melanoma centres are based in some public hospitals. At these centres, specialists in melanoma form a panel which can assess patients' cases and recommend the best treatment.

An expert histopathologist will review the biopsy of your melanoma to ensure that no error has been made and that there is no conflict of opinion about your diagnosis. You will be able to talk to an expert medical specialist, who will answer any difficult questions that you may have about your illness. You and your doctor will receive advice about your treatment.

As well as providing treatment advice, melanoma centres are involved in research studies and may invite you to become involved. They may also collect information about you and your melanoma for use in research. People who are at high risk of melanoma are sometimes invited to take part in research studies, even if they have not been diagnosed with melanoma.

You'll probably be asked if you would like to speak to a counsellor or psychologist with expertise in melanoma. They can help you cope with any challenges you face.

If you wish to attend a melanoma centre, ask your doctor about a referral.

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