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. Similar to adults, most pediatric cases (about 75%) are localized and have an excellent outcome.[70,76] More than 90% of children and adolescents with melanoma are expected to be alive 5 years after their initial diagnosis.[76,82,83,84]
The outcome for patients with nodal disease is intermediate, with about 60% expected to survive long term.[76,83] 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.
Prepubescent children with melanoma are more often non-white, have head and neck primary tumors, thicker primary lesions, and a higher incidence of spitzoid morphology, vascular invasion, and nodal metastases.[76,82,83,85]
The use of sentinel node biopsy for staging pediatric melanoma has become widespread, and the thickness of the primary tumor, as well as ulceration, have been correlated with a higher incidence of nodal involvment. Younger patients appear to have a higher incidence of nodal involvement; this finding does not appear to significantly impact clinical outcome in this population. In other series of pediatric melanoma, a higher incidence of nodal involvement did not appear to impact survival.[87,88,89] The association of thickness with clinical outcome is controversial in pediatric melanoma.[76,83,90,91,92] In addition, it is unclear why some variables that correlate with survival in adults are not replicated in children. One possible explanation for this difference might be the inclusion of patients who have lesions that are not true melanomas in the adult series; these patients are not included in pediatric trials.[93,94]
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.[76,82,83,85]
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]