A 13-year-old boy presented with a 3×4 cm, well demarcated, pale brown colored patch with multiple scattered, dark brown colored speckles, which were 2~3 mm in diameter, on the right side of neck, and these lesions were present since birth. At the age of 6, a white hypopigmented zone had developed around the nevus and it had gradually enlarged to 7 mm in diameter (Fig. 1A). In addition, vitiligo lesions were found in the periorbital, perinasal and perioral regions, simultaneously with the halo nevus (Fig. 1B). There was no personal or family history of autoimmune disorders. The histopathological findings of the hypopigmented lesion revealed a finding of decreased melanin in the basal layer of the epidermis, and the pale brown colored patch lesion revealed elongation of the rete ridges and increased melanin pigmentation in the basal layer of the epidermis (Fig. 2A).
Fig. 1. (A) A well demarcated, pale brown colored patch with multiple, scattered, dark brown speckles on the right side of the neck with a hypopigmented zone around the nevus. (B) In addition, lesions of vitiligo were found in the perioral, perinasal and periorbital regions.
A biopsy of the dark brown colored speckles showed increased melanin in the dermoepidermal junction and the upper der- mis (Fig. 2B). A finding of mononuclear inflammatory cell infiltrations in the upper part of the dermis was seen in the pale brown patch and the dark brown speckles. At present, the nevus persists, with no obvious sign of regression. The depigmented areas are unchanged, and no more vitiligo lesion has appeared.
Fig. 2. (A) The histopathology of the pale brown colored patch lesion revealed elongation of the rete ridges and increased melanin pigmentation in the basal layer of the epidermis. (B) Biopsy from the dark brown colored speckles showed increased melanin in the dermoepidermal junction and upper dermis. Mononuclear cells and lymphohistiocytes were infiltrated into the upper part of the dermis in both lesions (A, B) (S-100, x100).