Clark nevusClark nevus is a melanocytic nevus which shows architectural atypia. The atypical architectural features include asymmetry, irregular peripheral border of the lesion, shoulder phenomenon (extension of the junctional component of a compound nevus beyond its dermal component), lentiginous growth of solitary melanocytes along and focally in between elongated rete ridges, and bridging of junctional melanocytic nests.
While Clark nevus overlaps with dysplastic nevus, the terms are not interchangeable. The diagnosis of dysplastic nevus indicates both architectural and cytologic atypia. Clark nevus, while showing architectural atypia, is composed of cytologically unremarkable melanocytes.