Melanoma – What is Melanoma?

Melanoma can occur anywhere on the body but is more common in parts of the skin often exposed to sunlight. A new mole or a change in an existing one should be checked by a doctor straight away.


Normal moles are usually round with smooth edges, but melanoma shapes vary and most melanomas have uneven or not matching halves (asymmetrical). The colour may also be different from the surrounding skin.

Risk factors

It is important to note that not everyone who has risk factors for Melanoma will develop the disease. However, most cases of the disease are caused by UV-induced mutations and most of these are acquired. Some are due to certain genes that predispose people to the disease and others to a particular type of skin that is more sensitive to UV damage.

The incidence of melanoma has been increasing worldwide. It is much more common in fair-skinned populations where sun exposure is high, such as in Europe and the US, and in Australia where it can reach 60 per 100,000 people. The increase in melanoma has been observed across all age groups, but particularly in the over 60s.

Risk factors for Melanoma include:

People who have a history of one or more family members with Melanoma or who have been diagnosed with a previous Melanoma are at higher risk of developing the disease. The presence of a number of unusually shaped or coloured moles (dysplastic nevi) can also increase the risk, especially if they are large or raised.

Other risk factors for Melanoma include:


Melanomas usually develop in moles, freckles or other spots on the skin. They can grow quickly and are more dangerous when they break through the outer layer of skin (the epidermis) and enter the lower skin layers (the dermis). This is often when they begin to spread across the body.

A melanoma may be any colour from light brown to dark brown or black and it may have a raised bumpy appearance. It can also be asymmetrical, meaning one side doesn’t match the other. It may have uneven edges and be different in shape to other moles on the body. Melanomas tend to be bigger than normal moles and are more likely to change in size, shape or colour over time. They are also more common in areas exposed to the sun, such as the legs and arms but can be found on other parts of the body too, including the soles of the feet, palms of the hands and the genitals.

It is important to check your skin regularly for new or changing growths and to get any unusual ones checked by a GP. If a melanoma is caught early, it is more likely to be treated successfully. It is especially important for people with darker skin to be aware of the warning signs of melanoma and seek medical advice if they notice them.


If a GP is concerned about a mole or pigmented area of skin, they will arrange for it to be examined by a specialist, usually a dermatologist. They will take a detailed medical history, do a thorough examination including a total skin and lymph node examination and refer you for further investigations if needed.

Melanoma is a type of skin cancer that starts in cells called melanocytes. These are the cells that give our skin its colour. Melanomas are most often found on sun-damaged skin, but can develop anywhere on the body. There are different types of melanoma, each with a slightly different risk of developing into something dangerous.

The main tests used to diagnose melanoma are skin exams, blood tests and imaging tests such as a CT scan or an MRI scan. A biopsy is also sometimes required. This involves removing the suspicious mole, along with some surrounding skin tissue, under local anaesthetic. The sample is then examined under a microscope for signs of cancer.

Your GP may also recommend a sentinel lymph node biopsy to check if the melanoma has spread to your lymph nodes. In addition, they might recommend a biopsy of a nearby normal mole for comparison purposes. If they suspect that your melanoma has spread, they will discuss treatment options with you. This might include further surgery, chemotherapy, radiation therapy and immunotherapy.


For early melanoma, the usual treatment is surgery to remove the mole or lesion. A surgeon may also decide to remove nearby lymph nodes and other tissue. The sample of tissue is then examined under a microscope to check for cancer cells. If the melanoma has spread, further tests are needed to find out how far it has gone (staging).

Doctors can now use drugs to target specific genes or pathways that help cancer cells grow and survive. These are called targeted therapy or immunotherapy. One example is a drug that blocks the action of a protein called PD-1. It was approved by the FDA in 2020 as a single agent or in combination with other drugs for advanced melanoma that have a BRAF V600 mutation. Other PD-1 and PD-L1 inhibitors are being developed and studied.

Other treatments that can be used to treat melanoma include chemotherapy and radiation therapy. Before you go to your appointment, make a list of any medications, vitamins, or supplements that you take. You should also write down any symptoms or changes in your health that you’ve noticed. Also, take a family member or friend along to your appointment so they can remind you of any questions or concerns that you might forget.

Regular self-exams can also be important for detecting melanoma. It’s especially important to check areas that are exposed to the sun, such as your legs, arms, and face. It’s also a good idea to get someone to help you examine your back or other parts of the body that are hard to see.