Pediatric Melanoma and Atypical Melanocytic Neoplasms

Abstract

Melanoma is uncommon in the pediatric age range, but is increasing in frequency and often presents with atypical features compared to the classic ABCDE criteria common to adult melanoma cases. Moreover, many melanocytic neoplasms in childhood pose diagnostic challenges to the pathologist, and sometimes cannot be unequivocally classified as benign nevi or melanoma. This chapter addresses the evaluation and management of pediatric patients with melanoma and atypical melanocytic neoplasms, including the roles of and unresolved questions surrounding sentinel lymph node biopsy, completion lymphadenectomy, adjuvant therapy, and treatment of advanced disease.

Incidence and relative survival of melanoma in children and adolescents in the Netherlands, 1989–2013

“…In contrast to the trends in incidence of melanoma in adolescents, we observed stable incidences of melanomas in childhood (age 0–11 years). Risk factors for paediatric melanoma differ slightly depending on age at presentation . Main risk factors in adolescents are more similar to those in adults, namely: sun exposure, tanning bed use and fair skin, and are subject to trends.…”

“…Apart from trends, there is major difficulty in establishing whether or not a histologically abnormal melanocytic lesion in a child is malignant for sure. More frequently than in adults, lesions are non‐pigmented, have spitzoid features or are of nodular histology . A clinical difficulty in diagnosing paediatric melanoma is that around 50% of melanomas in children do not present with the conventional ABCD melanoma detection criteria .…”

“…The authors suggest this could be caused by real differences in the biology of the disease. It is noteworthy that while survival in children is high, the primary lesions in children are often thicker, and survival overall worsens with increasing Breslow thickness . Another possible cause is an incorrect diagnosis of melanoma in children, which leads to an artificial survival benefit.…”

“…We subdivided age into two groups: 0–11 (children) and 12–19 years (adolescents). This is based on a chosen cut‐off point of 12 years for adolescence, as in most studies age cut‐offs of 10–12 have been used to divide childhood from adolescent melanoma …”

“…Paediatric melanoma is a malignant melanocytic lesion in a child from birth to age of 18–21 years, depending on the cut‐off point used for defining adulthood . Melanoma is rare in childhood, with 15–40 cases per year over the past 25 years in the Netherlands, accounting for about 1% of melanoma cases in all ages .…”