Childhood melanoma is a rare but potentially fatal disease that is important to include in the differential diagnosis of any pigmented lesion in a child. The best prognosis is achieved with early diagnosis and definitive surgical excision. Adjuvant chemotherapy and immunotherapy are options for those with more advanced tumors. Melanoma in children must be treated as aggressively as in adults because childhood melanoma may be equally devastating.

The appearance of clonal nevi--tan with a focus of blue-gray to blue-black pigmentation--allows one to recognize the lesion clinically.

Although the classic halo nevus is a brown nevus with a surrounding rim of depigmentation, i.e. a stage I halo nevus, these nevi can have several clinical stages. The central nevus may lose its pigmentation and appear pink with a surrounding halo (stage II), the central papule may disappear leading to a circular area of depigmentation (stage III) or the depigmented area may repigment (stage IV), leaving no trace of its prior existence. Herein we describe an unusual phenomenon – darkening of the central nevus rather than lightening – following the appearance of the halo phenomenon. An 18-year-old boy who had multiple atypical nevi developed multiple halo nevi beginning at the age of 12 years. Following the appearance of the peripheral halos, 2 of his nevi that were originally solid medium brown in color darkened and the hyperpigmentation had a reticulated pattern with perifollicular sparing. One possible explanation is a postinflammatory hyperpigmentation induced by the infiltrating lymphocytes.

No abstract