Agminated Spitz nevi occurring within a congenital speckled lentiginous nevus

A 40-year-old woman had a speckled lentiginous nevus on her thigh since birth. During her first pregnancy, additional papules and nodules appeared within the preexisting hyperpigmented area, histologic examination of which showed features of both junctional and compound Spitz's nevi accompanied by simple lentigolike changes. In this particular case, speckled lentiginous nevus may have constituted a particular environment for the production of multiple Spitz nevi.