Discover essential information about melanoma and other types of skin cancer. Learn how to identify and treat these conditions.
Learn more about:
- What is melanoma?
- Other types of skin cancer
- The skin
- How common is melanoma?
- How do I spot a melanoma?
- The main types of melanoma
- What causes melanoma?
- Who is at risk?
- Having a family history of melanoma
What is melanoma?
Melanoma is a type of skin cancer. It develops in the skin cells called melanocytes.
Melanoma most often develops in areas that have been exposed to the sun.
It can also start in areas that don’t receive much sun, such as:
- the eye (uveal or ocular melanoma)
- nasal passages, mouth and genitals (mucosal melanoma)
- the soles of the feet or palms of the hands, and under the nails (acral melanoma).
Other types of skin cancer
Melanoma is not the only type of skin cancer. Other types of skin cancer, called non-melanoma skin cancers or keratinocyte cancers, are basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). These are far more common than melanoma.
However, melanoma is considered more serious because it can spread to other parts of the body, especially if not found early.
The skin
The skin is the largest organ of the body. It protects the body from injury, controls body temperature and prevents loss of body fluids.
The 2 main layers of the skin are called the epidermis and the dermis.
Below these is a layer of fatty tissue known as the hypodermis.
Epidermis
The epidermis is the top, outer layer of the skin. It is made up of several sublayers that work together to continually rebuild the surface of the skin. The main sublayers are the basal cell layer and the squamous cell layer.
| Squamous cell layer | This sits above the basal cell layer. Basal cells that have matured move up into the squamous cell layer. Here they are known as squamous cells or keratinocyte cells. Squamous cells are the main type of cell found in the epidermis. |
| Basal cell layer | This is the lowest layer of the epidermis. It contains basal cells and cells called melanocytes. The melanocyte cells produce a dark pigment called melanin, which gives skin its colour. When skin is exposed to ultraviolet (UV) radiation, melanocytes make melanin to try to protect the skin from getting burnt. This is what causes skin to tan. When melanocytes cluster together, they form non-cancerous spots on the skin called moles or naevi. |
Dermis
This layer of the skin sits below the epidermis. The dermis is made up of fibrous tissue and contains the roots of hairs (follicles), sweat glands, blood vessels, lymph vessels and nerves.
The layers of the skin
How common is melanoma?
Australia and New Zealand have the highest rates of melanoma in the world.
Each year in Australia, almost 19,000 people are diagnosed with invasive melanoma (it has spread into the dermis, the lower layer of the skin). and 28,000 people are diagnosed with melanoma in situ (it is only in the epidermis, the top layer).
In Australia, melanoma is the second most common cancer in men and the third most common in women (excluding non-melanoma skin cancers).
How do I spot a melanoma?
| When do new moles appear? | New moles mostly appear during childhood and through to the age of 30 to 40. However, adults of any age can develop new or changing spots. It is important to get to know your skin and check it every 3 to 6 months. |
| How to check your skin | To check your skin, make sure you are in a place with good light, undress completely 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. It is also a good idea to take a photo of your moles and spots so that you can compare them with an older photo to see if one has changed. |
| What to look for | How melanoma looks can vary greatly. Look for spots that are new, different from other spots, or raised, firm and growing. If you have lots of moles, a melanoma usually stands out and looks different from other moles. A melanoma is usually brown or black, but it can also be pink. |
| When to see a doctor | Even if your doctor has said a spot is benign in the past, check for any changes in shape, size or colour. If you notice a new or changing spot, get it checked as soon as possible by your doctor. |
What are the main types of melanoma?
Melanoma of the skin is known as cutaneous melanoma. There are 5 main subtypes of cutaneous melanoma:
Superficial spreading melanoma
| How common? | Makes up 55–60% of all melanomas. |
| Who gets it? | Most common type of melanoma in people under 40, but can occur at any age. |
| What does it look like? | Can start as a new brown or black spot that grows on the skin, or as an existing spot, freckle or mole that changes size, colour or shape. |
| Where is it found? | Can develop on any part of the body but especially the area between the shoulders and hip (trunk). |
| How does it grow? | Often grows slowly and becomes more dangerous when it invades the lower layer of the skin (dermis). |
Nodular melanoma
| How common? | Makes up about 10–15% of melanomas. |
| Who gets it? | Most commonly found in people over 65. |
| What does it look like? | Usually appears as a round, raised lump (nodule) on the skin that is pink, red, brown or black and feels firm to touch; may develop a crusty surface that bleeds easily. |
| Where is it found? | Usually found on sun-damaged skin. |
| How does it grow? | Often a fast-growing form of melanoma, spreading quickly into the lower layer of the skin (dermis). |
Lentigo maligna melanoma
| How common? | Makes up about 10–15% of melanomas. |
| Who gets it? | Most people with this subtype are over 40. |
| What does it look like? | Begins as a flat, irrregular patch of discoloured skin which can be brown, pink, red or white |
| Where is it found? | Mostly found on sun-damaged skin on the face, ears, neck or head. |
| How does it grow? | May grow slowly and superficially over many years before it grows deeper into the skin. |
Acral lentiginous melanoma
| How common? | Makes up about 1–2% of all cases. |
| Who gets it? | Mostly affects people over 40 with dark skin such as those of African, Asian and Hispanic backgrounds. |
| What does it look like? | Often appears as a colourless or lightly coloured area, may be mistaken for a stain, bruise or unusual wart; in the nails, can look like a long streak of pigment. |
| Where is it found? | Most commonly found on the palms of the hands, on the soles of the feet, or under the fingernails or toenails. |
| How does it grow? | Tends to grow slowly until it invades the lower layer of the skin (dermis). |
Desmoplastic melanoma
| How common? | Makes up about 1–2% of all cases. |
| Who gets it? | Mostly affects people over 60. |
| What does it look like? | Starts as a firm, growing lump, often the same colour as your skin; may be mistaken for a scar and can be difficult to diagnose. |
| Where is it found? | Mostly found on sun-damaged skin on the head or neck, including the lips, nose and ears. |
| How does it grow? | Tends to be slower to spread than other subtypes, but often diagnosed later; sometimes can invade or spread via nerves. |
Other types of melanoma
Some rarer types of melanoma start in other parts of the body. 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.
See Ocular melanoma or call 13 11 20 for more information about rarer types of melanoma.
For an overview of what to expect at every stage of your cancer care, visit Melanoma – Your guide to best cancer care. This is a short guide to what is recommended, from diagnosis to treatment and beyond.
What causes melanoma?
Exposure to ultraviolet (UV) radiation is the cause of most types of skin cancer. If unprotected skin is exposed to the sun when the UV index is 3 or above or to other UV radiation, the structure and behaviour of the cells can change.
This can permanently damage the skin, and the damage builds up every time a person spends time unprotected in the sun.
UV radiation most often comes from the sun, but it can also come from artificial sources such as solariums (also known as tanning beds or sun lamps). Solariums are now banned for commercial use in Australia because research shows that people who use solariums have a much greater risk of developing melanoma.
Who is at risk?
While anyone can develop melanoma, the risk is higher for people who have:
- unprotected exposure to UV radiation when the UV index is 3 or above, particularly a pattern of short, intense periods of sun exposure and sunburn, such as on weekends and holidays
- had significant UV exposure when they were young
- lots of moles (naevi), especially if the moles have an irregular shape and uneven colour
- pale or freckled skin, especially if it burns easily and doesn’t tan
- fair or red hair, and blue or green eyes
- a previous melanoma or other type of skin cancer
- a strong family history of melanoma
- a weakened immune system due to medical conditions or from using immunosuppressive medicines for a long time.
Family history of melanoma
Less than 2% of melanomas are linked to an inherited faulty gene. You could have an inherited faulty gene if 2 or more close relatives (parent, sibling or child) have been diagnosed with melanoma, particularly if they were diagnosed with more than one melanoma, or if they were diagnosed with melanoma before the age of 40.
People with a strong family history of melanoma should take extra care with sun protection and regularly check their skin carefully for new moles or skin spots. From their early 20s, they should consider having a professional skin check by a doctor.
If you are concerned about family risk, talk to your doctor about being referred to a family cancer clinic.
Visit Centre for Genetics Education to find a family cancer clinic near you. To learn more, call Cancer Council 13 11 20.
→ READ MORE: Melanoma symptoms
More resources
A/Prof Rachel Roberts-Thomson, Medical Oncologist, The Queen Elizabeth Hospital, SA; A/Prof Robyn Saw, Surgical Oncologist, Melanoma Institute Australia, Royal Prince Alfred Hospital and The University of Sydney, NSW; Alison Button-Sloan, Consumer; Dr Marcus Cheng, Radiation Oncologist Registrar, Alfred Health, VIC; Prof Anne Cust, Deputy Director, The Daffodil Centre, The University of Sydney and Cancer Council NSW, Chair, National Skin Cancer Committee, Cancer Council, and faculty member, Melanoma Institute Australia; Prof David Gyorki, Surgical Oncologist, Peter MacCallum Cancer Centre, VIC; Dr Rhonda Harvey, Mohs Surgeon, Dermatologist, Green Square Dermatology, The Skin Hospital, Darlinghurst and Sydney Melanoma Diagnostic Centre, RPA, NSW; David Hoffman, Consumer; A/Prof Jeremy Hudson, Southern Cross University, James Cook University, Chair of Dermatology RACGP, Clinical Director, North Queensland Skin Cancer, QLD; Dr Damien Kee, Medical Oncologist, Austin Health and Peter MacCallum Cancer Centre and Clinical Research Fellow, Walter & Eliza Hall Institute, VIC; Angelica Miller, Melanoma Community Support Nurse, Melanoma Institute Australia, WA; Romy Pham, 13 11 20 Consultant, QLD; A/Prof Sasha Senthi, Radiation Oncologist, Alfred Health, and Clinical Research Fellow, Victorian Cancer Agency, VIC; Dr Chistoph Sinz, Dermatologist, Melanoma Institute Australia, NSW; Dr Amelia Smit, Research Fellow, Melanoma and Skin Cancer, The Daffodil Centre, The University of Sydney and Cancer Council NSW; Nicole Taylor, Clinical Nurse Consultant, Crown Princess Mary Cancer Centre, Westmead Hospital, NSW.
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