Juvenile melanoma

1 to 4 % of all melanomas occur in children and adolescents < 20 years of age.

1.1% of patients in Australia with the first diagnosis of malignant melanoma were <20 years old.

Data from several studies show that the incidence rate increases after the age of 14.

A comparison showed an indication of greater tumour thickness in patients <10 years compared to patients >10 years.

w:m=1.7:1.0

The clinical picture of juvenile malignant melanoma does not differ from that of adults (see below Melanoma, malignant). A tendency to clinically atypical malignant melanomas such as amelanotic or even bizarre nodular growths is observed. Lentigo-maligna melanoma is not observed in children.

Clinical features apply to BK mole syndrome and to malignant melanomas on giant melanocytic nevi (see nevus , melanocytic, nevus giganteus below); in giant melanocytic nevi, malignant degenerations have been found either within the nevus or also extracutaneously in about 5% of patients. > 50% of all observed malignant degenerations occur within the first 5 years of life.

Basically, the therapy of malignant melanoma in children and adolescents does not differ from that of adults.

The question of sentinel lymph node biopsy has not been conclusively answered. However, it is recommended as in adults from a TD≥1.0mm. This recommendation is based on the statement of an Australian working group.

The median follow-up time in the above Australian study was 60 months (5-143 months) with an overall survival rate of 94.1% (48/51). The median tumor thickness in this collective was 1.7mm. The mean rate of positive SLNB was (astonishing) 25%.

The overall survival rate of the 14 patients with a positive SLNB at 60 months was 79% . In comparison, the overall survival rate at 60 months in a study of 356 adults with positive SLNB was 58%. From this, it can be concluded that the rate of positive SLNBs is higher in children and adolescents than in adults, but the survival rate is much more favorable (Howman-Giles R et al).

In a larger Dutch study, relative survival 1, 5, and 10 years after diagnosis was 98, 94, and 90%, respectively (Eggen CAM et al. 2018).

Ulceration, localization in the head and neck region, and Breslwo thickness >4.0mm predicted worse survival (El Sharouni MA et al. 2023).

1. Eggen CAM et al. (2018) Incidence and relative survival of melanoma in children and adolescents in the
   Netherlands, 1989-2013. J Eur Acad Dermatol Venereol 32:956-961.
2. El Sharouni MA et al (2023) Melanomas in children and adolescents: clinicopathologic features and survival outcomes. J Am Acad Dermatol 88:609-616.Hamm H et al (2011) Skin Tumors in Childhood. Dtsch Arztebl 108: 347-353.
3. Howman-Giles R et al (2010) Sentinel lymph node biopsy in pediatric and adolescent cutaneous melanoma patients. Ann Surg Oncol 17:138-143