Table 7. Characteristics of Paraganglioma (PGL) and Pheochromocytoma (PCC) Associated with Susceptibility Genesa continued...
Pediatric melanoma shares many similarities with adult melanoma, and the prognosis is stage dependent. Overall 5-year survival of children and adolescents with melanoma is approximately 90%.[78,84,85] Approximately three-fourths of all children and adolescents present with localized disease and have an excellent outcome (>90% 5-year survival). The outcome for patients with nodal disease is intermediate, with about 60% expected to survive long term.[78,85] In one study, the outcome for patients with metastatic disease was favorable, but this result was not duplicated in another study from the National Cancer Database.
In pediatric melanoma, the association of thickness with clinical outcome is controversial.[78,85,86,87,88] In addition, pediatric melanoma appears to have a higher incidence of nodal involvement and this feature does not appear to have an impact on survival.[89,90] However, it is unclear how these findings truly affect clinical outcome since some series have included patients with atypical melanocytic lesions.[91,92] In a study of sentinel lymph node biopsies in children and adolescents, 25% were positive (compared with 17% in adults). However, only 0.7% of lymph nodes found on complete lymph node dissection were positive for melanoma. In this study, mortality was infrequent but was confined to sentinel lymph node–positive patients.[Level of evidence: 3iiA] In another study, 53% of patients younger than 10 years had positive sentinel lymph node biopsy compared with 26% of those who were aged 10 years and older.
Children younger than 10 years who have melanoma often present with poor prognostic features, are more often non-white, have head and neck primary tumors, and more often have syndromes that predispose them to melanoma.[78,84,85,94]
Biopsy or excision is necessary to determine the diagnosis of any skin cancer. Diagnosis is necessary for decisions regarding additional treatment. Although BCCs and SCCs are generally curable with surgery alone, the treatment of melanoma requires greater consideration because of its potential for metastasis. The width of surgical margins in melanoma is dictated by the site, size, and thickness of the lesion and ranges from 0.5 cm for in situ lesions to 2 cm or more for thicker lesions. To achieve negative margins in children, wide excision with skin grafting may become necessary in selected cases. Examination of regional lymph nodes using sentinel lymph node biopsy has become routine in many centers [95,96] and is recommended in patients with lesions measuring more than 1 mm in thickness or in those whose lesions are 1 mm or less in thickness and have unfavorable features such as ulceration, Clark level of invasion IV or V, or mitosis rate of 1 per mm2 or higher.[95,97,98]