Table 8. Characteristics of Melanocytic Lesions
|Congenital nevi||BRAF,NRAS |
Surgery is the treatment of choice for patients with localized melanoma. Current guidelines recommend margins of resection as follows:
- 0.5 cm for melanoma in situ.
- 1.0 cm for melanoma thickness under 1 mm.
- 1 cm to 2 cm for melanoma thickness of 1.01 mm to 2 mm.
- 2 cm for tumor thickness greater than 2 mm.
Sentinel node biopsy should be offered to patients with thin lesions (≤1 mm) and ulceration, mitotic rate greater than 1 mm2, young age, and to patients with lesions greater than 1 mm with or without adverse features. Young patients have a higher incidence of sentinel node positivity and this feature adversely affects clinical outcomes. If the sentinel node is positive, patients should be offered the option to undergo a complete lymph node dissection. Patients with high-risk primary cutaneous melanoma, such as those with regional lymph node involvement, should be offered the option to receive adjuvant interferon alpha-2b, a therapy that is well tolerated in children.[99,100,115]
For patients with metastatic disease, prognosis is poor and various agents such as interferon, dacarbazine, temozolomide, sorafenib, or interleukin-2, and biochemotherapy can be used.[116,117,118] The results of pediatric trials that incorporate newer therapies such as vemurafenib and ipilimumab are not yet available.[119,120] Vemurafenib is used only in the treatment of patients with a BRAF mutation.
(Refer to the PDQ summary on adult Melanoma Treatment for more information.)
Basal cell and squamous cell carcinomas
Basal cell carcinomas (BCCs) 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 BCC syndrome (Gorlin syndrome) is a rare disorder with a predisposition to the development of early-onset neoplasms, including BCC, ovarian fibroma, and desmoplastic medulloblastoma.[123,124,125,126] SCCs are usually reddened lesions with varying degrees of scaling or crusting, and they have an appearance similar to eczema, infections, trauma, or psoriasis.
Diagnostic evaluation and treatment
Biopsy or excision is necessary to determine the diagnosis of any skin cancer. Diagnosis is necessary for decisions regarding additional treatment. BCCs and SCCs are generally curable with surgery alone and further diagnostic workup is not indicated.
Most BCCs have activation of the hedgehog pathway, generally resulting from mutations in PTCH1. Vismodegib (GDC-0449), a hedgehog pathway inhibitor, has been approved for the treatment of adult patients with BCC.[128,129] It was approved by the U.S. Food and Drug Administration for the treatment of adults with metastatic BCC or with locally advanced BCC that has recurred following surgery or who are not candidates for surgery, and who are not candidates for radiation. This drug also reduces the tumor burden in patients with basal cell nevus syndrome.