What is melanoma?

Melanoma is a type of skin cancer. It develops in the skin cells called melanocytes and usually occurs on parts of the body that have been overexposed to the sun. Rare melanomas can also start inside the eye or in a part of the skin or body that has never been exposed to the sun, such as the mucous membrane (e.g., sinuses, digestive tract, genitals), the soles of the feet or palms of the hands and under the nails.

Although it is one of the less common types of skin cancer, melanoma is considered the most serious types of skin cancer because it is more likely to spread to other parts of the body, especially if not detected early. The earlier melanoma is found, the more successful treatment is likely to be.

Types of melanoma

Melanoma of the skin is known as cutaneous melanoma. The major subtypes are:

Superficial spreading melanoma

This makes up 55-60% of all melanomas. It is most common in people under 40, but can occur at any age. It can start as a new brown or black spot that grows on the surface of the skin, or an existing spot, freckle or mole that changes size, colour or shape. It can develop on any part of the body but especially the trunk. This type of melanoma often grows slowly and becomes more dangerous when it invades the lower layer of the skin (dermis)

Nodular melanoma

This type makes up about 10-15% of melanomas. It is most commonly found in people over 65. It usually appears as a round, raised lump (nodule) on the surface of the skin that is pink, red, brown or black and feels firm to touch. It may develop a crusty surface that bleeds easily. Nodular melanoma is most commonly found on the head and neck. It is a fast-growing form of melanoma, spreading quickly into the lower layer of the skin (dermis).

Lentigo maligna melanoma

This type makes up about 10-15% of melanoma. This subtype is most common in people over 40. It begins as a large coloured spot (lentigo maligna) in an area of sun-damaged skin, such as the face, ears, neck and head. It may grow slowly and superficially over many years before it penetrates more deeply into the skin.

Acral lentiginous melanoma

This is a rare type of melanoma (about 1-2% of all cases). It mostly affects people over 40. It is most commonly found on the palms of the hands or on the soles of the feet, or under the fingernails or toenails. It commonly appears as a colourless or lightly coloured area, which may be mistaken for a stain, bruise or unusual wart; in the nails it can look like a long streak of pigment in the nail. It tends to grow slowly before becoming invasive.

Desmoplastic melanoma

This is another rare type of melanoma (about 1-2% of cases). It often affects people over 60 and appears on the head and neck of sun-damaged skin. Desmoplastic melanoma starts as a firm, growing frequently skin coloured lump, sometimes described as scar-like. Some have a patch of overlaying pigmentation and can be difficult to diagnose.

Other types of melanoma

Some rarer types of melanoma start in part of the body other than the skin. Mucosal melanoma can start in the tissues in the mouth, anus, urethra, vagina or nasal passages. Ocular melanoma can start inside the eye. Melanoma can also start in the central nervous system.

How common is melanoma?

Australia and New Zealand have the highest rates of melanoma in the world. More than 4180 people are estimated to be diagnosed with melanoma in Queensland every year. Melanoma is the second most common cancer in men and women.

What causes melanoma?

The main cause of all types of skin cancer is overexposure to UV radiation from the sun or another source, such as solariums (tanning beds). Solariums are now banned in Australia for commercial use because research shows that people who use solariums have a significantly greater risk of developing melanoma.

When your unprotected skin is exposed to UV radiation, the structure and behaviour of the cells can change.

Risk factors

Anyone can develop melanoma, however, the risk is higher in people who have:

• Unprotected exposure to UV radiation
• Lots of moles (naevi) – more than 10 moles above the elbow on the arms and more than 50 on the body
• Moles with irregular shape and uneven colour (dysplastic naevi)
• A previous melanoma or other type of skin cancer
• A strong family history of melanoma
• Pale, fair or freckled skin, especially if it burns easily and doesn’t tan
• Light coloured eyes (blue or green), and fair or red hair
• A weakened immune system from using immune suppression medicines for a long time.

Overexposure to UV radiation can permanently damage the skin. This damage adds up over time. Childhood exposure to UV radiation increases the risk of skin cancer later in life, although sun protection will help prevent melanoma at any age.

Symptoms

Melanoma looks can vary greatly. In you have lots of moles, a melanoma usually stands out and looks different from the other moles. The first sign is often a new spot or a change in an existing mole.

• Size – The spot may appear or grow larger.
• Colour – The mole may become increasingly blotchy with different depth and shades of colour (brown, black, blue, red, white, light grey, pink or skin-coloured).
• Shape or border – The spot may increase in height, become scaly, have an irregular edge (scalloped or notched) or lack symmetry (the halves look different).
• Itching or bleeding – The mole may itch or bleed at times.
• Elevation – the spot may start as a raised nodule or develop a raised area, which is often reddish or reddish brown.

New moles can appear during childhood and through to the 30s and 40s, as well as during pregnancy. However, adults of any age can have new and changing spots. It is important to get to know your skin and check it regularly. In a room with good light, fully undress and use a full-length mirror to check your whole body. For areas that are hard to see, use a handheld mirror or ask someone to help.

See you doctor if you notice a freckle, mole or lump that is NEW or CHANGING in size, shape or colour, or a sore that does not heal over 4-6 weeks.

Diagnosis

Physical examination – if you notice any changes to your skin, your doctor will examine you, looking carefully at any spots you have identified as changed or suspicious. The doctor will ask if you or your family have a history of melanoma.

Removing the mole (excision biopsy) – If the doctor suspects that a spot on your skin may be melanoma, the whole spot is removed for examination by a tissue specialist (pathologist). This is generally a simple procedure done in your doctors office. Your GP may do it, or you may be referred to a dermatologist or surgeon.

Checking the lymph nodes – The lymph nodes are part of your body’s lymphatic system, which helps to protect the body against disease and infection. The lymphatic system is a network of vessels, tissues and organs. There are large groups of lymph nodes in your neck, armpits and groin. Sometimes melanoma can travel through the lymphatic system.

Treatment

Melanoma that is found early (stages 0-2) can generally be treated successfully with surgery alone. If the melanoma has spread to nearby lymph nodes or tissues (stage III or regional melanoma), treatment may also include removing lymph nodes and additional (adjuvant) treatments.

• Surgery to remove the mole is the main treatment for early melanoma and it can also be the only treatment you need.
• Removing the lymph nodes – Occasionally, melanoma may spread to lymph nodes and cause lumps that your doctor can feel during physical examination. If a fine needle biopsy confirms that a lymph node contains melanoma, that group of lymph nodes may be removed in an operation called a lymph node dissection or lymphadenectomy. This is performed under a general anaesthetic and requires a longer stay in hospital .
• Adjuvant therapies – if there is a risk that the melanoma could come back (recur) after surgery, other treatments are sometimes used to reduce that risk. There are known as an adjuvant (or additional) treatment. They may be used alone or together and can include immunotherapy, targeted therapy or radiation therapy.

Prognosis

Prognosis means the predicted outcome of a disease. You may wish to discuss your prognosis and treatment options with your doctor, but it is not possible for any doctor to predict the exact course of the disease. Instead, your doctor can discuss any concerns you have.

Melanoma can be treated most effectively in its early stages when it is still confined to the top layer of the skin (epidermis). The deeper a melanoma penetrates into the lower layers of the skin, the greater the risk that it could spread to the nearby lymph nodes or other organs.

In recent years, clinical trials have led to new treatments that continue to improve the prognosis for people with melanoma that has spread from the primary site (advanced or metastatic melanoma).

Discussing your prognosis and thinking about the future can be challenging and stressful. It may help to talk with family and friends. You can also call Cancer Council 13 11 20 if you need more information or emotional support.

Support for Queenslanders

Whether you have been diagnosed with a melanoma, or have a family member or friend who is affected by cancer, there are times when you may need support. Our professional services and support programs are here to help you.

Find out more about:

• Phone support
• Email support
• Cancer counselling
• Practical and financial support
• Support groups
• Information sessions

You don’t have to face cancer alone – we’re here to help.

Resources

For more information about melanoma and skin cancer, please see these resources

If you are a patient, family or friend and would like a copy of either the Understanding Skin Cancer or Understanding Melanoma booklet, please call Cancer Council 13 11 20