Author: Natasha Gattey, M.D. Candidate, Class of 2016 College of Medicine, University of Saskatchewan, Canada.Chief Editor: Dr Amanda Oakley, Dermatologist, Hamilton, New Zealand, December 2014.
Melanoma is a skin cancer that arises from melanocytes (pigment-producing cells). Childhood melanoma usually refers to melanoma diagnosed in individuals under the age of 18 years. It is rare.
For more information about melanoma, see:
Melanoma arising in children has been classified into the following types :
Specific kinds of melanoma are described in detail elsewhere on DermNet NZ: see melanoma resources. Some features notable in childhood melanoma are discussed here.
Melanoma in older children appears similar to melanoma in adults; it presents as a growing lesion that looks different from the child's other lesions. Most are pigmented. About 60% have the ABCDE criteria:
|B: Border irregularity|
|C: Colour variation|
|D: Diameter >6 mm|
Superficial spreading melanoma is less common in younger children and melanoma has the ABCDE criteria in 40% of cases.
Melanoma in young children is more commonly amelanotic (red coloured), nodular, and tends to be thicker at diagnosis than in older children and adults.
Cordoro et al (2013) have suggested adding additional ABCD detection criteria for skin lesions in children :
|A: Amelanotic (the lesion is skin coloured or red)|
|B: Bleeding, Bump|
|C: Colour uniformity|
|D: De novo, any Diameter|
Small congenital naevi arise in 1 in 100 births. Melanoma is a rare complication of small to medium congenital naevi. It tends to appear on the edge of the birthmark and is recognised by change within the mole and the ABCDE criteria described above.
The risk of melanoma is higher in larger congenital naevi [7,8]. Melanoma arises in about 4% of children 10 years or younger that have a giant congenital melanocytic naevus >40 cm in diameter. Giant congenital melanocytic naevi are very rare, arising in 1 in 20,000 births. In giant congenital melanocytic naevi:
These melanomas can be difficult to detect early. Excision may also be difficult or impossible.
Common moles are usually easy to recognise and are uniform in structure and colour. They remain fairly stable once they have reached their final size.
Red skin nodules that can be confused with melanoma in children include Spitz naevus and pyogenic granuloma. Both of these look different from the child's other skin spots and tend to progressively enlarge. Pyogenic granuloma is prone to bleed easily. Benign proliferative nodules can arise within congenital naevi.
Cutaneous melanoma in children is rare, and extremely rare before puberty . It comprises 3% of all paediatric cancers . However, in New Zealand, melanoma is the second most common cancer registration in people aged 0–24 years .
Risk factors for childhood melanoma include: [4,5].
Like the adult population, melanoma mainly affects Caucasian children and is associated with sun exposure. There is a slight female preponderance [4,6].
Treatment of childhood melanoma is the same as in adults. In New Zealand:
Metastatic melanoma or advanced melanoma is melanoma that has spread to lymph nodes or elsewhere in the body. Treatment is individualised but may include surgery, radiotherapy, chemotherapy or targeted therapy.
Prognosis of melanoma depends on the stage of melanoma, ie whether it has spread beyond its original site in the skin. Spread of melanoma to lymph nodes and elsewhere is more likely in thicker tumours (measured by Breslow thickness at the time of removal of a primary tumour).
Survival rates are similar in older children and adults [2,3]. However, melanomas in children under 11 years of age appear to have a less aggressive behaviour than those detected in adults [4,5].
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