What do we know about cutaneous melanoma of childhood?

DR. FERRARI is in the pediatric oncology unit, DRs. BONO and SANTINAMI are in the melanoma and sarcoma unit, DR. COLLINI is in the pathology department, and DR. RODOLFO is in the melanoma genetics unit, all at Istituto Nazionale per lo Studio e la Cura dei Tumori, Milano, Italy.

Although the incidence of cutaneous melanoma in childhood is rare, it appears to be rising.^1,2 At The Istituto Nazionale Tumori (INT) of Milan, Italy, we recently reported the clinical findings in, and treatment and outcome of, 33 prepubertal patients seen for cutaneous melanoma from 1975 to 2001.¹ Together with other recent papers, this contribution has fired the discussion on melanoma in children. Melanoma presents differently in children than it does in adults, and pediatricians who evaluate pigmented skin lesions must be aware of those diagnostic clues so that the diagnosis is not missed.

A worldwide snapshot of incidence

The growing number of cases appears to be associated with cumulative ultraviolet light exposure in childhood. The latitude at which a person lives and his or her skin type and pigmentation also may have a role. Melanoma is more likely to develop in a fair-skinned patient, particularly one who has red hair, than in a dark-skinned patient.

The cause of melanoma is, of course, complicated, with family history and susceptibility genes-including CDKNZA and CD4K, whose penetrance might be altered by genetic or environmental factors-also having a role.^12-14 Exposure to sunlight has, nonetheless, been variously measured (number of blistering sunburn episodes, time reportedly spent outdoors) and case-control studies in adults demonstrate that sun exposure confers a two- to five-fold increase in the risk of melanoma.^15,16 Despite these findings, the US Preventive Services Task Force guidelines recommend regular total body skin examinations only for adults older than 20 years: No screening guidelines exist for children and adolescents.

Little is known about management of melanoma in childhood. Prospective trials are not feasible, and retrospective studies generally include only a handful of patients, compared with adult studies.¹⁷ The majority of patients described in the pediatric literature are in their late teens and few are younger than 10 years.^18-26 Consequently, management strategies for pigmented skin lesions in children are generally extrapolated from experience with adults.^20,27

The INT Milan series