Osteonevus of Nanta in a 3-year-old child with dermatoscopic characterization.

Osteonevus of Nanta is a rare and peculiar benign skin lesion, histologically characterized by the presence of osseous metaplasia in a melanocytic nevus.1 This condition was first described in an intradermal nevus by Heidingsfeld in 1908 and later named osteonevus of Nanta in 1911; since then, cases of osseous metaplasia occurring in blue and combined nevi have also been reported.2,3 Osteonevus of Nanta is commonly diagnosed in adults, with most cases being reported in women between the fourth and the fifth decades of life.