Cutaneous malignant melanoma is a cancer of the pigment cells of the skin. If it is treated early, the outlook is usually good. It is not contagious.
Early diagnosis is crucial for malignant melanoma
Melanomas can be seen early as they appear clearly on the skin. They can be cured, if they are caught early enough and a simple operation can be performed under local anaesthetic to remove them.
Suspicious moles will be removed for analysis, but more often than not a mole is benign when it is removed, in other words non- cancerous, but it is important to be safe and sure.
If melanoma is spotted early and treated quickly then it is completely curable but if left it becomes thicker and can spread to other internal organs (metastasise) from the skin.
Moles and malignant melanoma what are they?
The average adult has between 15- 40 moles, which appear between childhood and up to the age of 40 years. A mole is made of a collection of melanocyte pigment cells, which give the mole its colour. Melanocytes are cells in the skin that make the pigment called melanin. Melanin absorbs the ultraviolet light from the sun and protects the skin from damage caused by it.
Moles are normal and appear in childhood. The more sunlight a child is exposed to can increase the number of moles. Some families have many moles on the skin, which is normal for those family members as the number of moles is under the control of genes.
Below is shown a few moles that nearly all of us have. There are raised ones and flat ones, but it is CHANGING ones that you need to look out for. A mole or melanocytic naevus is made up of pigment cells.
A pigment producing cell is called a melanocyte and they produce melanin, which is the brown pigment that gives a tan. A malignant melanoma is a skin cancer arising from pigment producing cells.
A melanoma can arise within an existing mole by the melanocytes becoming malignant or cancerous. This will be noted as a change in a mole.
What is cancer?
The word “cancer” comes from the Latin word that means “crab”. This is because the appearance of a cancer, or tumour, was considered to look like a crab when found in human tissue.
There are many types of cancer, some more serious than others. They occur when cells that normally divide very carefully break loose of this control and divide too quickly, out of control and build up a mass or tumour. Tumour just means swelling.
Sometimes these cancers can spread to other parts of the body. Otherwise they stay where they started.
Cells divide to reporoduce under very strict genetic control. Damage to the genes can break this control leaving cells to divide rapidly causing a cancer.
There are 3 major types of skin cancer that are caused by the sun. The most common is basal cell carcinoma, the next is squamous cell carcinoma and then there is malignant melanoma.
Basal cell carcinoma does not spread and so is not so serious. It does need removing.
Squamous cell carcinoma is usually found as a lump with a crust on the skin and again needs to be removed before it damages nearby structures on the skin.
Malignant melanoma, seen left, affects about 6000 people in the UK and about 2000 people die each year with it. It appears pigmented, in other words brown, and can look like a mole. The difference is that these can spread to other parts of the body. This is more likely to happen the longer that they are left. It is for this reason that it is important to have a mole checked early.
The number of people suffering from a malignant melanoma has risen dramatically in recent years.
Australia has the highest incidence of melanoma with approximately 40 new cases per 100,000 of the population being affected annually.
In Europe the risk is less with approximately 13- 21 per 100,000 being affected.
Sunbathing risk factor for melanoma
The most important factor responsible for causing various types of skin cancer is the ultraviolet light from the sun. Melanin, a pigment found in the skin, protects the skin from this radiation. However, for people with Caucasian types of skin, getting a tan just shows that the skin has had to produce some melanin and that it has therefore been damaged by sunlight.
There is no doubt that sun exposure causes skin cancer and melanoma. The figures speak for themselves in Australia, New Zealand, South Africa and California, places where people with white coloured skin live in intense sunlight.
It is thought it is the intermittent intensive exposure to sunlight leading to sporadic episodes of severe sunburn (such as you might get from a yearly 'sun worshipping' holiday abroad) that increases the risk of melanoma not just a long history of chronic exposure.
This probably accounts for the increased incidence of melanoma generally, as increasing numbers of people (especially young adults) now holiday abroad in sunny climates.
Those that are ill prepared will get sunburnt.
Children are particularly at risk of sunburn. Sunbeds give off artificial ultraviolet light so can increase the risk of developing a melanoma. Paying for a sunbed is paying for increasing your risk of skin cancer. That doesn’t make sense does it?!
You want to sunbathe? Are you sure! Having a tan, means the skin has been damaged by the ultraviolet UV light.
The attitude in the UK towards the sun is completely different to the attitude of Australians for example where a major public health campaign has educated the population about the risks of sunlight.
There is no such thing as safe sunbathing.
Having a tan can make people feel happier but is a tan worth the risk? A fake tan is safe.
At what age does melanoma start?
The commonest age of patients presenting with a melanoma is between 50- 60 years but there is a worrying trend with the incidence increasing in the 20- 30 year age group.
New genetic discovery
The new discovery of a gene involved in malignant melanoma is exciting. The research was published online in the journal Nature. The gene that has been discovered is in a group of genes that control how cells divide. What has been found is that malignant melanoma cells have a bit of damaged DNA within a gene that has allowed the cells to divide out of control. The gene involved was the BRAF gene, which undergoes a simple mutation probably caused by sunlight amongst other things. This mutation was found in only 66% of the malignant melanomas that were tested. What is exactly going on in the other malignant melanomas is not clear.
The promise is that a drug can be developed to turn off this gene and therefore potentially turn off the melanoma. However there is a great deal of further research needed to develop a drug to achieve this.
Skin type risk factors for melanoma
Why some people are more likely to get melanoma is not fully understood. There are genetic and racial factors but the most important predisposing factor is excessive exposure to sunshine or ultraviolet light.
Melanoma is rare in dark skin races, due to their natural protection from the sun.
Individuals with red hair, blue eyes, fair complexion and freckles, who sunburn easily, are said to be the most vulnerable and need to take extra care in the sun. These people are referred to as having skin type 1.
Skin types reacting to sunlight:
Type I: Very sensitive, always burns easily going very red in sunlight, never tans
Type II: Very sensitive, always burns going red after sunlight, minimal tan after
Type III: Sensitive , burns moderately going red, tans gradually after with a light tan
Type IV: Moderately sensitive rarely going red, tans easily going brown
Type V: Minimally sensitive, rarely burns, going brown always, dark brown
Type VI: Never burns, always deeply pigmented, black
Malignant melanoma stands out from the crowd usually, but can be difficult to spot sometimes.
Generally a melanoma will appear different to the other moles. So simply, if any mole is becoming different from its neighbours it should be shown to a doctor.
However very rarely a melanoma can just be red. this is called an "amelanotic melanoma" where the pigment cells (melanocytes) cannot make the melanin because theyhave turned cancerous and so it is just red.
Worrying change normally occurs over weeks to months, not gradually over years as all our moles mature as we do.
If in doubt, check it out - see your doctor
The picture left is of a melanoma. It had CHANGED by becoming darker, with irregular pigment, becoming more raised and with irregular border and less symmetrical.
The important thing is to look out for changes in moles. If a mole is CHANGING with any of the following then document, even take a photograph of the mole and seek advice from your doctor.
If any mole shows any of these features it should be looked at by your doctor.
Change in colour
Is the mole a different colour from all the others?
Has the mole recently become darker brown, black or even paler in colour?
Does the colour seem very irregular and different depending on which part of the mole you study?
Change in size
Is the mole suddenly larger than all the others?
Has it grown recently?
Has an area become more lumpy or raised?
Change in shape
Is the mole a different shape from all the others?
Has the mole developed an irregular edge or outline? Is it easy to draw round with a pen or is the outline too irregular?
It is the story of any change in a mole which is crucial
Below is a raised mole that was normal because it had not changed and had no symptoms.
THE ABCDE criteria
A - Asymmetry: instead of being symmetrical the mole becomes irregular
B - Border: instead of the border of the mole being smooth and well defined the border becomes irregular
C - Colour: instead of the mole being the same colour throughout and staying that way, if the mole becomes variable in colour with some dark and some light areas in it.
D - Diameter greater than 6mm
E - Elevation – instead of being smooth, the mole becomes raised and lumpy
E - expert - seek advice from an expert
Bleeding and itching and pain in a mole are also signs that need to be taken seriously.
NB: some people have many moles with the above features, but that is normal for them.
If there is any doubt, then seek medical advice.
Other suspicious signs from moles include:
Crusting on the surface
Redness around the mole
Sometimes a mole can be caught on clothing, such as bra straps or waist bands. If they become inflamed they can also become itchy and can be scratched causing further inflammation. If this is the case the symptoms will settle down, but if they persist then contact a doctor.
How often should I check my moles?
Everybody should check their moles and their families / partners moles every 6 months or so (or more regularly if there is a family history of melanoma).
Where should I look for a melanoma?
Most melanomas strangely appear on an area of skin not previously inhabited by a mole.
As we should not be getting new moles past 40 years of age, any new "mole" that appears after this time should be treated with suspicion.
Some melanomas do of course arise from previous atypical or completely normal looking moles and it is the story of change that will accompany this transformation which is crucial and should again arise suspicion.
Taking a biopsy of a suspected Melanoma
All suspect moles / melanomas are removed surgically usually under a local anaesthetic (patient awake).
For a biopsy a 1mm border around the mole is taken and the whole mole should be sent for analysis.
Removal by operation
If a melanoma is confirmed, then the thickness determines how wide a further area of skin should be taken away. The exact details of surgery would depend on the size and site of the mole, as well as the age and wishes of the patient.
If a large area of skin needs to be removed then a general anaesthetic and skin graft may be needed.
If any further treatment is required, for instance chemotherapy, patients are usually referred to a specialist centre for expert assessment and treatment.
Patients are usually followed up in hospital for at least 3 years, following removal of the melanoma with three monthly appointments for the first year and 6 monthly thereafter.