Spontaneous partial repigmentation of halo nevi around congenital melanocytic nevus and vitiligo in a 13-year-old boy

摘要

Halo nevi (HN) or leukoderma acquisitum centrifugum is a ring of depigmentation that may appear around acquired or congenital melanocytic nevi (CMN) as well as melanoma. In some cases, the hypopigmented halo anticipates the total or partial regression of the melanocytic lesion, while in others it remains stable or eventually undergoes repigmentation. HN is not uncommon, being more frequent around acquired melanocytic nevus. Up to 26% of patients with HN have vitiligo, but in very few instances is there an association of HN around CMN and vitiligo. The exact mechanisms responsible for the development of vitiligo and HN and its resolution are unknown. One of the most accepted hypotheses considers that both phenomena are a result of a self-limited immunologic response to pigmented cells, either in the '"normal"' skin or within the melanocytic lesion. We report a case of halo CMN that subsequently developed vitiligo and spontaneous partial repigmentation of both lesions.