Pediatric Occurrence of Osteonevus of Nanta: A Case Report

Secondary ossification is a process that occurs in various cutaneous conditions. When this occurs within a melanocytic nevus, it is termed Osteonevus of Nanta (ON). This rare phenomenon typically presents in elderly female individuals usually located on the upper trunk. In this report, we present a unique presentation of ON in a pediatric patient. A 2-year-old female with no significant past medical history presented to a plastic surgeon for excision of an asymptomatic soft tissue mass on the right scalp. The parents described the gradual postnatal development of the 1.2 x 0.4 x 0.3 cm red-brown nodule. Excisional biopsy was performed and histopathological analysis found the lesion to be most consistent with ON. To our knowledge, there are no other published reports of ON in the pediatric population. This exceedingly rare case serves to expand our current understanding of this lesion and may provide further insight into the pathogenesis of these nevi.