A 25-year-old woman consulted for a pigmented lesion on her right arm.The lesion was a lentiginous patch with darker brown pigmented macules in favor of a nevus spilus.
Dermoscopy revealed darker brown areas with a reticulo-globular pattern in favor of melanocytic nevi. The background was light brown and reticular.
Nevus spilus are present at birth or childhood. On histology they correspond to a lentigo with surimposed junctional or compound nevi.Main differential diagnosis is agminated nevus which correspond to lentiginous compound melanocytic nevi without light background pigmentation.
Reference: Bragg et al. Agminated acquired melanocytic nevi of the common and dysplastic type. J Am Acad Dermatol 2005;52:67-73