Xanthomatous nevus: a new entity or a fortuitous collision?

Xanthomas are non-neoplastic, localized lipid deposits within the dermis and subcutis. They can present as papules, plaques, or nodules. Different clinical variants include eruptive, tuberous, tendinous, papular, plane, and verruciform xanthomas. They can occur at any age and can be idiopathic or suggest the presence of an underlying disorder of lipoprotein metabolism. The association between a xanthoma and congenital melanocytic nevus (CMN) has never been reported. Here, we present the first case and hypothesize on its etiology.