A Case of Halo Congenital Nevus

Yang, Yun Seok; Shin, Min Kyung; Lee, Mu Hyoung

Abstract

The term halo congenital nevus is a condition in which halo formation is associated with congenital melanocytic nevus. The regression of congenital melanocytic nevi is usually accompanied by the halo phenomenon and this is considered to be a rare event, although this may be underestimated. We describe here a 9-year-old boy with verrucous congenital nevus surrounded by a depigmented halo on the right upper arm. Histologically, the nevus lesion revealed a dense lymphocytic infiltration in the upper dermis intermingled with some remnants of nevus cell nests. Most of the infiltrating cells were CD8+ T lymphocytes. At the edge of the lesion, corresponding to the area of the halo, neither melanocytes nor melanin were found in any significant amounts.