Introduction
Types
Clinical features
Differential diagnoses
Demographics
Treatment
Outlook
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: 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+EFG criteria.
Superficial early melanoma:
A: Asymmetry |
B: Border irregularity |
C: Colour variation |
D: Different |
E: Evolving |
Nodular melanoma:
E: Elevated |
F: Firm |
G: Growing |
Superficial spreading melanoma is less common in younger children and the melanoma has the ABCDE signs 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. Nodular melanoma has the EFG signs - Elevated, Firm, Growing.
Additional ABCD detection criteria for skin lesions in children have been suggested:
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 with a higher risk associated with large congenital naevi and overall risk for all CMN 1-2%. Melanoma is also associated with multiple congenital naevi even in the absence of a giant CMN. It tends to appear on the edge of the birthmark and is recognised by change within the melanocytic naevus (mole) and the ABCDE+EFG criteria described above.
Melanoma arises in up to 15% of children 10 years or younger with a giant congenital melanocytic naevus >40 cm in diameter (G3) particularly if associated with neurocutaneous melanocytosis. Such 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:
Like the adult population, melanoma mainly affects Caucasian children and is associated with sun exposure. There is a slight female preponderance.
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. However, melanomas in children under 11 years of age appear to have a less aggressive behaviour than those detected in adults.
