Pediatric melanoma shares many similarities with adult melanoma, and the prognosis is stage dependent. In pediatric melanoma, however, thickness does not appear to correlate with outcome in localized invasive disease.[47,59,60,61] 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.[62,63] However, it is unclear how these findings truly affect clinical outcome since some series have included patients with atypical melanocytic lesions.[64,65] 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] 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.[47,58,60]
Basal cell carcinomas generally appear as raised lumps or ulcerated lesions, usually in areas with previous sun exposure. These tumors may be multiple and exacerbated by radiation therapy. Nevoid basal cell carcinoma syndrome (Gorlin syndrome) is a rare disorder with a predisposition to the development of early-onset neoplasms, including basal cell carcinoma, ovarian fibroma, and desmoplastic medulloblastoma.[69,70,71,72] SCCs are usually reddened lesions with varying degrees of scaling or crusting, and they have an appearance similar to eczema, infections, trauma, or psoriasis.
Biopsy or excision is necessary to determine the diagnosis of any skin cancer. Diagnosis is necessary for decisions regarding additional treatment. Basal and squamous cell carcinomas are generally curable with surgery alone, but 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[73,74] 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.[73,75,76] Lymph node dissection is recommended if sentinel nodes are involved with tumor, and adjuvant therapy with high-dose interferon-alpha-2b for a period of 1 year should be considered in these patients.[40,73,77,78,79] Clinically benign melanocytic lesions can sometimes pose a significant diagnostic challenge, especially when they involve regional lymph nodes.[80,81,82]