People with only CMN on the skin and no other features have just CMN.  If however there are any other associated features, the term CMN syndrome can be used.  A syndrome is a collection of findings in one individual that can potentially be explained by the same genetic change. The term CMN syndrome is useful to alert healthcare professionals to aspects other than the skin.

a. Facial features

Research has found that many children with CMN have a similar looking face. This is a normal face, and in fact usually a very attractive face, but it is similar to other children with CMN. This is likely to be caused by the same mutation that causes the skin changes and the brain changes (when there are any).

b. Weight

This has been found in a large group of patients at Great Ormond Street Hospital (GOSH), but it is an average finding. In other words, it was found found that on average the children with CMN gained weight faster than those without, but this did not apply to everyone, many have normal weight gain. It is not yet clear what causes this weight gain, but it seems to respond to the usual recommendations of eating more healthily and increasing the amount of exercise, so it is useful to know about and address it.

It is important for parents to ensure that their children do not become overweight in childhood, as it is a very difficult problem to address in teenage and adult years. It can be very difficult for an individual with CMN to cope with being overweight. In addition, being overweight in adulthood is bad for the person’s overall health.

c. Hormonal systems

Some children with CMN have early breast development. This has been found to be mild and harmless, and does not usually need any treatment. It also does not seem to lead to early puberty. It is however always sensible to inform the child’s doctor. Undescended testes also seem to be an associated problem in boys with bathing trunk distribution CMN (in the shorts area). These need to be reviewed by a urologist to discuss whether they need to be surgically corrected. Some children with CMN involving the genital area in both sexes have had issues with how the genitals are formed by the time of birth. This can usually be helped by surgical correction if needed.

d. Neurological problems

Neurological problems associated with CMN used to be called Neurocutaneous melanosis. This term is no longer used for two important reasons. The first reason is that some of the problems are not actually “melanosis”, in other words they are not a problem of pigment cells. The second reason is that in the medical literature neurocutaneous melanosis is often actually melanoma of the brain or spinal cord, and this has caused big problems with trying to advise families on diagnosis. We now prefer to call the neurological problems by their actual names – so if it is benign intraparenchymal melanosis (e.g. moles in the brain) we say so, and if it is melanoma of the brain or spine we say so. This allows us to give better information to parents and patients, and has allowed us to divide the causes into serious and less serious. Overall, problems in the brain or spinal cord are the most common complication seen in children with CMN. The most common problem is pigment-containing cells (like a CMN) in the substance of the brain. This is called intraparenchymal melanosis. Other rarer problems include benign brain or spinal tumours, too much fluid in the brain, or abnormal brain structure. All of these neurological problems are more common with larger and more numerous CMN. Our current recommendations are that any child born with two or more CMN should have a routine MRI scan of the brain and spine, preferably by the age of 6 months.The overall chance of finding an abnormality on an MRI scan in children with multiple CMN (two or more at birth) is around 20%, but only around half of these children will have any actual problems. If they do have problems these can be fits (convulsions), developmental delay, or problems with their limbs. It is possible to have problems in development even when the scan is normal, but these tend to be milder.

The most common problem with neuro development is a delay in speech. For children with more than one CMN it is very common to have a delay in speech in the first few years of life. This usually presents itself as a problem with expressive speech- the child’s ability to express what they’re saying whenever they usually understand everything.
This usually catches up with time, as a rule of thumb it could easily be delayed six months but then would catch up. If this problem persisted over time for longer than six months, we would encourage a parent to seek medical advice.
– Why should children with CMN have an MRI? A brain MRI is recommended for every child with born with multiple CMN (more than one at the time of birth, any size or site) to determine the presence of any internal pigment in the brain or nervous system. An earlier MRI allows for a clearer scan, ideally under 6 months of age. The MRI looks for the rare cases of congenital benign tumours and extra fluid on the brain that require an operation, and for the commoner “moles in the brain” which need monitoring of child development more carefully. Some findings alert doctors to monitor children more carefully for the development of melanoma, by having more MRIs. Most children however will only have one scan.
Not only do we recommend this single screening scan, but anyone with multiple CMN (more than one at birth) who develops new problems over their lifetime with development or fits, or persistent headaches over a long period, or any problems which could be due to brain or spine disease, should have a repeat MRI to look for the development of melanoma.

e. Risk of melanoma

Histology (the study of cells under a microscope) of CMN is difficult and often requires specialist review. A review should be carried out by at least two experts in the field. A genetic analysis of an individual’s CMN can help to differentiate melanoma from benign nodules in the skin, or from stable congenital disease in the Central Nervous System.
Small single CMN are common birthmarks with very low risk of melanoma, and do not require routine resection for this reason. Multiple CMN have a higher risk of melanoma due to larger area of skin covered. Different people with different types of CMN have different risks of melanoma; however, the overall absolute risk for all types of CMN taken together is low. Where melanoma does arise in children with multiple CMN, a primary melanoma in the Central Nervous System is more common than in the skin. The strongest statistical risk factor for all‐site melanoma in childhood is an abnormal screening MRI of the Central Nervous System (CNS) in the first 6 months of life. When melanoma does develop in CMN it is highly aggressive. Central Nervous System melanoma currently has 100% mortality, however recent treatments with a drug called Trametinib helps to reduce symptoms and can possibly extend life. We continue to fund pioneering research to find the cure for CMN through our partnership with Professor Kinsler and her research team. We have a vision of a world where no one suffers from CMN.

What if I find a new lump or bump in my CMN?
CMN can develop nodules that can cause uncertainty. Histology (the study of cells under a microscope) is difficult and often requires specialist review. Review should be carried out by at least two experts in the field. A genetic analysis of an individual’s CMN can help to differentiate melanoma from benign nodules in the skin, or from stable congenital disease.

Other questions people ask about melamona

Does suntan, as opposed to sunburn, increase the chance of damage or Melanoma in CMN?

We definitely don’t want children to get sunburned, we also don’t really like them to get suntanned much. That’s true, in general, for skin and dermatology in children. This is the general advice that we give to all our patients.

As for the role of sunlight in CMN, nobody has done a study as to whether UV light and your exposure to sunshine makes a difference to your chance of getting CMN. CMN develops in the brain first, it’s not something that is affected by UV light.

It is possible that the amount of sunlight you are exposed to as a child might make a difference to your chance of getting Melanoma as an adult, and that is just the same for all of us.

Sun exposure in childhood is important for your chance of getting Melanoma later in life, so in general we would like to avoid that if possible- to avoid sunburns and suntan where you can.

This answer has been taken from a Q&A zoom session with Professor Veronica Kinsler, recorded in April 2020.
Please note this is an accurate answer at the time of recording. However, due to the continuing advancement in CMN research, it is important to seek current guidance and advice from a medical professional or by contacting Caring Matters Now.  You can watch the full recorded session here.

Is the risk chance of Melanoma different with different sizes of CMN?

If you only have one CMN then yes, a smaller one, has less chance than a larger one. However, if you only have one CMN the chance of getting Melanoma at all in the CMN is very low in your lifetime.

If you have lots of CMN, to some degree it matters but we have found is it is not as important as the MRI scan finding. If your MRI scan is normal your overall risk of getting Melanoma in childhood, even with lots of CMN, is still low (1 to 2%).

If you have some brain abnormalities, it probably doesn’t matter what size your nevi is. We don’t know that for sure, but it’s the abnormal scan that matters from what we understand. This finding is likely to change overtime.

This answer has been taken from a Q&A zoom session with Professor Veronica Kinsler, recorded in April 2020.
Please note this is an accurate answer at the time of recording. However, due to the continuing advancement in CMN research, it is important to seek current guidance and advice from a medical professional or by contacting Caring Matters Now.  You can watch the full recorded session here.

What percentage of people who have brain abnormalities with CMN develop Melanoma?

If you have an MRI scan in the first year of life which is normal, your chance of developing melanoma seems to be lower than in people who have abnormalities seen on the brain MRI. It is not clear why this, one of the most obvious reasons is that a lot of the melanoma that develops in childhood starts in the brain or spinal cord. Because of that, it might mean that if you can see abnormalities in the brain, on the scan, that maybe that increases your chance. It is clear from the data that if you have a normal scan, in the first year of life, you have lower chance of getting melanoma, at least in childhood. We don’t know if that’s true into adulthood as we only have data from a childhood cohort, up to the age of about 18 years old.

Exact risks are difficult to give people as it depends on your individual CMN and scan.
The most common finding on a scan is something which we call ‘Intraparenchymal Melanosis,’ this is where little groups of melanin containing cells- a bit like little nevi are seen inside the brain itself. This probably doesn’t increase your chance of Melanoma much at all. What seems to be more of an issue is whenever you have problems along the coating of the spine or brain, or if there are many different structural problems in the brain.

These are much rarer findings, but these more complicated abnormalities increase the risk of Melanoma in childhood. We are lucky in the UK because we have a system, and because of work done by my predecessor, there is already a cohort established meaning we’ve been able to follow people up for a long time. What we have found is that people who have an abnormal scan, in the first year of life, have a 10-15% chance of getting Melanoma in childhood. However, this won’t be the same for everybody as it depends uniquely on what is found on your MRI scan. The vast majority of cases will not get Melanoma.

This answer has been taken from a Q&A zoom session with Professor Veronica Kinsler, recorded in April 2020.
Please note this is an accurate answer at the time of recording. However, due to the continuing advancement in CMN research, it is important to seek current guidance and advice from a medical professional or by contacting Caring Matters Now.  You can watch the full recorded session here.

Are the chances of getting Melanoma different for people who have different genes?

At the moment, as far as we know, there is no difference in the chance of getting Melanoma depending on which gene is causing your CMN.

We also know that there doesn’t seem to be any difference in the chance of having neurological problems with different genes. This seems to be something that can happen with any of the types of genes.

Going forward, as we understand more that may change. Our understanding at the moment is that you don’t need routine gene testing for CMN because it doesn’t change your chance of getting problems with the brain or your chances of getting Melanoma.

The one time that we would suggest getting a test for either the NRAS or BRAF gene, is if somebody actually develops Melanoma or where Melanoma is strongly suspected. The reason that it’s worth testing for the gene is because it changes the type of treatment that you might be given. This is a very well-known test and is very well understood by dermatologists and oncologists already, so you would automatically be offered that testing if someone thought you had Melanoma.

This answer has been taken from a Q&A zoom session with Professor Veronica Kinsler, recorded in April 2020.
Please note this is an accurate answer at the time of recording. However, due to the continuing advancement in CMN research, it is important to seek current guidance and advice from a medical professional or by contacting Caring Matters Now.  You can watch the full recorded session here.

Should people who have CMN, or their families, need to be generally screened for cancers?

No, there is no evidence to tell us that people need to be screened for cancers in general. There are some families who are prone to cancers but we do not know of any connection between that and CMN at the moment.

This answer has been taken from a Q&A zoom session with Professor Veronica Kinsler, recorded in April 2020.
Please note this is an accurate answer at the time of recording. However, due to the continuing advancement in CMN research, it is important to seek current guidance and advice from a medical professional or by contacting Caring Matters Now.  You can watch the full recorded session here.

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