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Every CMN is unique. There is no specific pattern of distribution or skin texture within the nevus itself and no way to be certain just how having a CMN will affect a person’s lifestyle. Below are some of the most common questions answered, however each case is individual and will have its own particular areas of concern. Malignant Melanoma Melanoma is a cancer of melanocytes, the skin cells which produce pigment and which make up congenital melanocytic nevus. It used to be thought that melanoma was very common in people with CMN, but we now know that it is rare, occurring in around 1-2% of all people with CMN over their lifetime. However, the risk is higher in people with very large and numerous CMN, perhaps as much as 10%, and there is a peak of risk during childhood. When considering these risks, you need to bear in mind that a person without a CMN still has a risk of about 40% of developing some kind of malignant cancer at some time in his or her lifetime. Melanoma in people with congenital melanocytic nevus can occur anywhere, not just within the CMN, and not just in children. It can present as a lump in the CMN, in another area of skin, or in the lymph nodes (which are throughout the body). However, melanoma is rarely if ever found in a disseminated “satellite” nevus. In about half the cases, it occurs directly within the brain or spine, when it can present with persistent headaches with nausea/vomiting, or visual disturbances, balance problems or seizures, like other tumors. Unfortunately, when malignant melanoma occurs in a person with a congenital melanocytic nevus, it is often aggressive and difficult to treat. Our recommendations are that any rapidly changing area should be reviewed by an experienced doctor, who can decide whether a biopsy is required. Do remember however, that nodules, lumps and color changes appear frequently in congenital melanocytic nevi, and they are almost as frequently, completely harmless. Serial photographs, the use of dermoscopy, palpation of nevus and scars, examination of lymph nodes and a thorough review of systems may aid physicians in early detection of melanoma. Also, only experienced pathologists can avoid the trap of finding a growing CMN nodule “melanoma-like”; if such a report comes to you, it is worth asking for a second opinion. In Australia there is a system of checks that occurs during pathological testing that reduces greatly any risk of false results. We recommend that children who develop any new neurological problems such as recurrent headaches, visual disturbances, seizures, or developmental changes should be seen urgently by specialist doctors, such as a paediatric neurologist and a neuroradiologist, in a major paediatric hospital if at all possible. Skin Problems Fragility Many congenital melanocytic nevi are more delicate than normal skin, especially in newborns. They can therefore tear more easily if they are knocked or scraped. However, they do not bleed any more than normal skin, and they tend to heal well with minimal scarring. Treat as any superficial scrape or wound on non-nevus skin, cleaning with soap and water, and use of an antiseptic ointment and a bandage. Dryness and itching The lack of oil glands and increased hair growth along with the CMN’s naturally volatile nature also has the potential to lead to a problem with dryness and itching. It has recently been discovered that this may be a result of an increase in mast cells in the nevus skin as well as the ‘normal’ skin of the CMN patient. This is the same extreme itching usually associated with eczema. Steroid and non steroid creams can help as can moisturisers and emollients particularly oils. Heat or cold can aggravate this condition. Ice packs can sometimes help. This extreme itching can also occur in scar tissue. It is possible for the child to break the skin while scratching. Decrease in subcutaneous fat This is usually only seen with larger congenital melanocytic nevi. For some reason, the presence of the CMN interferes with setting up the layer of fat that is normally present between the skin and underlying muscle and bone. This can result in the nevus appearing to be depressed below the general skin surface, the limb, buttock or side of the face, and appearing obviously thinner than normal. Overheating The skin of a CMN is often lacking in subcutaneous fat. It also generally has no sweat glands or oils glands within the pigmented areas plus will often have increased hair growth. This makes it very difficult for the body to lose heat through the pigmented areas of skin or equally through any scar tissues that may be present due to surgical intervention. Overheating can be a major problem in some patients with CMN. Modern climate controls make this easier to manage however be aware if you are planning sports sessions or are in a non air conditioned environment that this is taken into consideration. It is not necessary to exclude children from sports sessions nor does this help their psychosocial outcomes. Planning outdoor activities for the mornings or evenings during warmer months helps. Heat stress and heat exhaustion can occur very quickly and are potentially life threatening. Some ways to manage overheating include the use of cooling vests, cold face washers, cool foot baths, splashing face and head with cool water, quiet time in a cool spot. Occasionally a child may need to be withheld from attending activities during extreme heatwaves. Neurological Problems Problems in the brain or spinal cord are the most common serious complication seen in children with congenital melanocytic nevus. Because the pigment cells found in the skin and (yes, normally in) the meninges develop from the same cells as the brain in the early embryo, people with CMN can also have differences in their brain or spinal cord. Approximately one in fifteen to twenty people with large and giant forms of CMN have excess pigment cells in the brain or spinal cord. This can lead to a complication known as neurocutaneous melanocytosis (NCM). Earlier studies often used the term “melanosis”-the first means more pigment cells, and the second means more pigment. The difference is not easy to determine non-invasively. Other much rarer problems include benign brain or spinal tumors or cysts, too much fluid in the brain (hydrocephalus), or abnormal brain structure. All of these neurological problems are more common with larger and more numerous CMN, but there is no connection with the site of the CMN. In other words, having a congenital melanocytic nevus overlying the brain or spine does not increase the chance of having neurological problems. Should a Person with a CMN have Magnetic Resonance Imaging (MRI)? Current recommendations in Australia are that any child born with a large or giant congenital Nevus and multiple satellite lesions (generally 20 or more) in any location should have a routine MRI scan of the brain and spine, preferably by the age of six months, though there is no strict cutoff age. It is not possible to say that MRI abnormalities could never occur in children with only one CMN at birth, but the likelihood is much less. The overall chance of finding any kind of abnormality on brain and spinal MRI scan in children with large and multiple CMN may be as high as 25%, but only around half of these will have any actual neurological problems.Things to look out for include: epileptic convulsions (fits/seizures), developmental delay, limb coordination issues, frequent vomiting or headaches not linked to an infection or fever, and tiptoeing or late bed-wetting, which can be signs of a tethered spinal cord. (And which are also quite frequent in children and should not alarm you.) It is possible to have problems in development even when the scan is normal, but these tend to be milder. The reason for doing the scan is to pick up the rare cases of tumors, cysts and extra fluid on the brain that require an operation, and to allow more careful neurological monitoring of those children with MRI findings. The pigment cells in the brain or spine cannot currently be treated themselves, but the epilepsy that sometimes occurs in NCM can respond to conventional medication and surgical approaches, as can a tethered spinal cord or cysts. We also recommend that children with congenital melanocytic nevi larger than 20 cm (8 inches) projected adult diameter be followed up regularly to watch their neurological development, even if they do not have more than one nevus. In addition, any child with any type of CMN who has neurological symptoms like those described above should have an MRI. These neurological problems tend not to afflict adults with CMN if they had not started during childhood or adolescence. Psychological Challenges People with congenital melanocytic nevi sometimes attract looks, stares, whispering and finger-pointing. Children who grow up with a prominent congenital melanocytic nevi or many congenital melanocytic nevi may well have problems adjusting to the disfigurement that they perceive, particularly during the teenage years. This, however, is a very individual thing, and varies depending on the child’s personality and on the support from family and friends. The problems may manifest as anxiety, depression, or lowered self-esteem. Family members sometimes hope that a nevus will ‘fade’ and the other potential medical challenges will also disappear. Some large congenital melanocytic nevi can lighten over time, but the birthmark itself, and potential challenges, remain. This reality requires not only the person with the CMN, but also their loved ones, to take some time to adapt. Obviously with a visible physical difference the potential for psychosocial problems arise. Different children manage questions and stares in different ways and we recommend that you talk with your child regarding how they feel comfortable having questions answered. A very effective response is that it’s a birthmark, it doesn’t hurt and you can’t catch it. Bullying is an issue and can often be quite subtle but hurtful in nature. The impact of this will also vary from child to child. This can also be affected by the gender of the child and the location of the pigmented skin and/or scar tissue. Sometimes areas where nevus tissue has been removed can look like burns scarring. It is thought that over 30% of patients with CMN will suffer from depression and/or anxiety specifically related to the psychosocial pressures related to their CMN. Depending on the age of the child and the parent’s personal preference, some will be aware of the health risks associated with their CMN others will not. Becoming aware of this can for a while at least, place extra pressure on the wellbeing of the child. We recommend place a high value on the child’s wellbeing and emotional health. In a school situation, school counsellors, guidance officers and pastoral care workers can play an important role in supporting the child. Bullying Teasing and bullying can be a problem. There is much written on the subject of managing bullying and the value of zero tolerance practices. It is of value to keep strong lines of communication open between home and the care environment to help address any problems as they arise. Will they grow out of it? No. This is a lifelong condition. The nevus may change over time, it may fade slightly (not disappear), get darker, get hairier, but it will not go away. So what is the general prognosis? Honestly we don’t really know. CMN patients have only been really followed for about the last 15 years or so in the UK and USA to see what happens. Nevus Support Australia has been around for 12 years. We have no national birth register so have no way of tracking outcomes for patients. Thankfully this is slowly changing. We do know that there are older CMN patients out there, some of them have married and had children of their own. So is it hereditary? We don’t think so. There are a few cases where there is more than one member of a family with a large nevus but not with a giant CMN as far as we know at the moment. As far as we are aware no one with a CMN has had a child with a CMN nor have any siblings. There are cases where twins and triplets have been born with one affected by CMN and the others not. So our best guess at the moment is that no it is not hereditary, it is just one of those things that we can’t explain. There is a lot of ongoing research to try to find the answers. So how does this child/person fit into normal life? These are normal children/people who have special skin. They want and need to feel just like any other child/person. Younger children will need your help to remind them to stay out of the sun and in the cool, even on warm not hot days. A day over about 25 degrees can get hot quickly. Other than being sun safe and aware of overheating, treat your CMN child as you would any other child.
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This information on this website is for general information purposes only. It is not intended as a medical reference. Please talk with your doctor for medical advice.
There are a number of risks and considerations with CMN