THE DEVELOPMENT OF LENTIGINES WITHIN SEGMENTAL ACHROMIC NEVI

The classic definition of a nevus depigmentosus is a stable congenital leukoderma that may be localized, segmental, or less often, systemati zed. Herein we report 2 patients whose achromic nevi underwent an unus ual change-the development of multiple lentigines. The lentigines rang ed in size from 3 to 5 mm and the majority had an irregular outline. A lthough their color was darker than that of the normal surrounding ski n, the most striking clinical finding was their limited distribution. The lentigines were present only within the confines of the nevus depi gmentosus. They first appeared at age 3 years in 1 child and at age 1 year in the second. No new pigmented macules were noted in the older c hild after age 10 years and, by that time, greater than 90% of the nev us depigmentosus was ''repigmented.'' One possible explanation would b e the reversion of a mutation in 1 of the genes involved in pigmentati on.