Symptoms of melanoma skin cancer


Symptoms of melanoma skin cancer

Symptoms of melanoma 

The first sign of a melanoma is often a new mole or a change in the appearance of an existing mole.

Normal moles are usually round or oval, with a smooth edge, and no bigger than 6mm (1/4 inch) in diameter.

See your GP as soon as possible if you notice changes in a mole, freckle or patch of skin, especially if the changes happen over a few weeks or months.

Signs to look out for include a mole that is:

getting bigger

changing shape

changing colour

bleeding or becoming crusty

itchy or painful

A helpful way to tell the difference between a normal mole and a melanoma is the ABCDE checklist:

Asymmetrical – melanomas have two very different halves and are an irregular shape.

Border – melanomas have a notched or ragged border.

Colours – melanomas will be a mix of two or more colours.

Diameter – melanomas are larger than 6mm (1/4 inch) in diameter.

Enlargement or elevation – a mole that changes size over time is more likely to be a melanoma.

Melanomas can appear anywhere on your body, but they most commonly appear on the back, legs, arms and face. They may sometimes develop underneath a nail.

In rare cases, melanoma can develop in the eye. Noticing a dark spot or changes in vision can be signs, although it is more likely to be diagnosed during a routine eye examination.

Want to know more?

Cancer Research UK: Melanoma symptoms.

Causes of melanoma 

Most skin cancer is caused by ultraviolet (UV) light damaging the DNA in skin cells. The main source of UV light is sunlight.

Sunlight contains three types of UV light:

ultraviolet A (UVA)

ultraviolet B (UVB)

ultraviolet C (UVC)

UVC is filtered out by the Earth's atmosphere, but UVA and UVB damage skin over time, making it more likely for skin cancers to develop. UVB is thought to be the main cause of skin cancer.

Artificial sources of light, such as sunlamps and tanning beds, also increase your risk of developing skin cancer.

Repeated sunburn, either by the sun or artificial sources of light, increases the risk of melanoma in people of all ages.


You are at an increased risk of melanoma if you have lots of moles on your body, especially if they are large (over 5mm) or unusually shaped.

Having just one unusually shaped or very large mole increases your risk of melanoma by 60%.

For this reason, it's important to monitor moles for changes and avoid exposing them to the sun.

Family history

Research suggests that if you have two or more close relatives who have had non-melanoma skin cancer, your chances of developing the condition may be increased.

Increased risk

Certain things are believed to increase your chances of developing all types of skin cancer, including:

pale skin that does not tan easily

red or blonde hair

blue eyes

older age

a large number of freckles

an area of skin previously damaged by burning or radiotherapy treatment

a condition that suppresses your immune system – such as HIV

medicines that suppress your immune system (immunosuppressants) – commonly used after organ transplants

exposure to certain chemicals – such as creosote and arsenic

a previous diagnosis of skin cancer

Want to know more?

Cancer Research UK: Melanoma risks and causes.


Diagnosing melanoma 

A diagnosis of melanoma will usually begin with an examination of your skin. Your GP will refer you to a specialist if they suspect melanoma. 

Some GPs take digital photographs of suspected tumours so they can email them to a specialist for assessment.

As melanoma is a relatively rare condition, many GPs will only see a case every few years. It's important to monitor your moles and return to your GP if you notice any changes. Taking photos to document any changes will help with diagnosis.

Seeing a specialist

You will be referred to a dermatology clinic or hospital for further testing if melanoma is suspected. You should see a specialist within two weeks of seeing your GP.

The dermatologist or plastic surgeon will examine the mole and the rest of your skin. They may also remove the mole and send it for testing (biopsy) to check whether the mole is cancerous. A biopsy is usually carried out under local anaesthetic, meaning the area around the mole will be numbed and you won't feel any pain.

If cancer is confirmed, you will usually need a further operation, most often carried out by a plastic surgeon, to remove a wider area of skin.

Further tests

Further tests will be carried out if there is a concern the cancer has spread into other organs, bones or your bloodstream.

Sentinel lymph node biopsy

If melanoma spreads, it will usually begin spreading through channels in the skin (called lymphatics) to the nearest group of glands (called lymph nodes). Lymph nodes are part of the body’s immune system, helping to remove unwanted bacteria and particles from the body.

Sentinel lymph node biopsy is a test to determine whether microscopic amounts of melanoma (less than would show up on any X-ray or scan) might have spread to the lymph nodes. It is usually carried out by a specialist plastic surgeon, while you are under general anaesthetic.

A combination of blue dye and a weak radioactive chemical is injected around your scar. This is usually done just before the wider area of skin is removed. The solution follows the same channels in the skin as any melanoma.

The first lymph node this reaches is known as the “sentinel” lymph node. The surgeon can locate and remove the sentinel node, leaving the others intact. The node is then examined for microscopic specks of melanoma (this process can take several weeks).

If the sentinel lymph node is clear of melanoma, it's extremely unlikely that any other lymph nodes are affected. This can be reassuring because if melanoma spreads to the lymph nodes, it's more likely to spread elsewhere.

If the sentinel lymph node contains melanoma, there is a risk that other lymph nodes in the same group will contain melanoma.

Your surgeon should discuss the pros and cons of having a sentinel lymph node biopsy before you agree to the procedure. Sentinel lymph node biopsy does not cure melanoma, but is used to investigate the outlook of your condition.

An operation to remove the remaining lymph nodes in the group may be recommended. This is known as a completion lymph node dissection or completion lymphadenectomy.

Other tests you may have include:

a computerised tomography (CT) scan

a magnetic resonance imaging (MRI) scan

a positron emission tomography (PET) scan

blood tests

Want to know more?

Cancer Research UK: Melanoma tests.

Cancer Research UK: Further tests for melanoma.


Treating melanoma 

Surgery is the main treatment for melanoma, although it often depends on your individual circumstances.

People with melanoma skin cancer should be cared for by a team of specialists that often includes a dermatologist, a plastic surgeon, an oncologist (a radiotherapy and chemotherapy specialist), a pathologist and a specialist nurse.

When helping you decide on your treatment, the team will consider:

the type of cancer you have

the stage of your cancer (how big it is and how far it has spread)

your general health

Your team will recommend what they believe to be the best treatment option, but the final decision will be yours.

Before going to hospital to discuss your treatment options, you may find it useful to write a list of questions to ask the specialist. For example, you may want to find out what the advantages and disadvantages of particular treatments are.

Staging melanoma hide

Health professionals use a staging system to describe how far melanoma has grown into the skin (the thickness) and whether it has spread. The type of treatment you receive will depend on what stage the melanoma has reached.

The stages of melanoma can be described as:

Stage 0 – the melanoma is on the surface of the skin.  

Stage 1A – the melanoma is less than 1mm thick.

Stage 1B – the melanoma is 1-2mm thick, or the melanoma is less than 1mm thick and the surface of the skin is broken (ulcerated) or its cells are dividing faster than usual (mitotic activity).

Stage 2A – the melanoma is 2-4mm thick, or the melanoma is 1-2mm thick and is ulcerated.

Stage 2B – the melanoma is thicker than 4mm, or the melanoma is 2-4mm thick and ulcerated.

Stage 2C – the melanoma is thicker than 4mm and ulcerated.

Stage 3A – the melanoma has spread into one to three nearby lymph nodes, but they are not enlarged; the melanoma is not ulcerated and has not spread further.

Stage 3B – the melanoma is ulcerated and has spread into one to three nearby lymph nodes but they are not enlarged, or the melanoma is not ulcerated and has spread into one to three nearby lymph nodes and they are enlarged, or the melanoma has spread to small areas of skin or lymphatic channels, but not to nearby lymph nodes.

Stage 3C – the melanoma is ulcerated and has spread into one to three nearby lymph nodes and they are enlarged, or the melanoma has spread into four or more lymph nodes nearby.

Stage 4 – the melanoma cells have spread to other areas of the body, such as the lungs, brain or other parts of the skin.

Want to know more?

Cancer Research UK: Treating melanoma.

Cancer Research UK: Stages of melanoma.

Macmillan: Malignant melanoma.


Preventing melanoma 

The best way to prevent all types of skin cancer is to avoid overexposure to the sun.

A few minutes in the sun can help maintain healthy levels of vitamin D, which is essential for healthy bones, but it's important to avoid getting sunburn.

Once you are burnt, the damage has already been done to your skin, as it has received a dangerous level of radiation. Every time the skin is exposed to radiation, this increases the chance of a cancer occurring, possibly many years in the future.

Some simple steps to manage your sun exposure are outlined below.

Avoid the sun when it is at its hottest

The sun is usually at its hottest between 11am and 3pm, but can also be very strong and have potentially damaging effects at other times.

Do not spend long periods of time in the sun during the day. Make sure you spend time in the shade, and cover up with clothes and sunscreen.

Dress sensibly

If you cannot avoid spending long periods of time in the sun – for example, if you work outdoors – wear clothes that will provide sun protection.

This should include a hat to protect your face and scalp, and sunglasses to protect your eyes. When buying sunglasses, look for:

the CE or British Standard mark (BS EN 1836: 2005)

a UV 400 label

a label saying the glasses give 100% UV protection

Use sunscreen

When buying sunscreen, make sure it's suitable for your skin type and blocks both ultraviolet A (UVA) and ultraviolet B (UVB) radiation. A sun protection factor (SPF) of at least 15 is recommended.

Sunscreen should be applied around 15 minutes before you go into the sun and reapplied every two hours. If you are planning to spend time in the water, use a waterproof sunscreen.

Take extra care to protect babies and children. Their skin is much more sensitive than adult skin, and repeated exposure to sunlight could lead to skin cancer developing in later life. Before going out into the sun, make sure your children are dressed appropriately and are wearing a hat and a high SPF sunscreen.

Tan sensibly

Most health professionals will tell you to avoid sunbathing altogether, because even a tan can increase your risk of developing skin cancer.

However, if you are determined to get a tan, do it gradually by limiting the amount of time you spend in the sun each day and by wearing sunscreen.

When you begin to tan, limit your exposure to the sun to 30 minutes, then gradually increase it by five or 10 minutes a day.

Sunbeds and sunlamps

The British Association of Dermatologists is the UK's leading professional body on skincare. It advises that people should not use sunbeds or sunlamps.

Sunbeds and lamps can be more dangerous than natural sunlight, because they use a concentrated source of ultraviolet (UV) radiation.

UV radiation can increase your risk of developing melanomas. Sunbeds and sunlamps can also cause premature skin ageing.

If you continue to use sunbeds or sunlamps, the Health and Safety Executive (HSE) has issued advice on the health risks linked to UV tanning equipment, which includes sunbeds, sunlamps and tanning booths. It recommends you do not use UV tanning equipment if:

you have fair, sensitive skin that burns easily or tans slowly or poorly

you have a history of sunburn, particularly in childhood

you have lots of freckles or red hair

you have lots of moles

you are taking medicines or using creams that make your skin sensitive to sunlight

you have a medical condition made worse by sunlight

you have had skin cancer or someone in your family has had skin cancer

sunlight has already badly damaged your skin

The HSE's advice also includes important points to consider before you decide to use a sunbed. For example, if you use a sunbed, the operator should advise you on your skin type and how many minutes you should use the machine for.

It is now illegal for under-18s to use sunbeds. The Sunbeds (Regulation) Act, which came into force in April 2011, prevents those under 18 from:

being allowed to use tanning salons and sunbeds at premises, including beauty salons, leisure centres, gyms and hotels

being offered the use of a sunbed

being allowed to be in an area reserved for sunbed users

Check your moles

As well as staying safe in the sun, you should regularly check any moles for signs of melanoma.

See your GP if you notice any changes to your moles or freckles, as this can lead to an early diagnosis and improve your chances of successful treatment.

Want to know more?

Cancer Research UK: SunSmart.

HSE: Reducing health risks from the use of ultraviolet (UV) tanning equipment (PDF, 93kb).