A 24-year-old man was admitted to our outpatient clinic with lesions in a linear configuration. On dermatologic examination, widespread, dark brown, warty papules and plaques over an erythematous base, following Blaschko"s lines, extended from the middle of the chest to the right arm. These lesions had been present on the chest since birth and had gradually extended during childhood. Recently, a nodular lesion had appeared in the pre-existing epidermal nevus in the middle part of the chest (Fig. 1). The nodular lesion was totally excised by a plastic surgeon.