Ectopic plantar nail: a report of two cases.

Ectopic nail is an extremely rare condition related to acquired or congenital anomalies. Almost 40 cases are reported in the literature, mostly in Japanese patients. In the majority of these patients, ectopic nails developed in the dorsal aspect of the fingers; they are associated in some cases with acquired or congenital growth anomalies or to polydactyly. Recently, we observed two male adult patients with true ectopic nails of the foot (sole and heel). Both patients were not affected by ectodermic dysplasia or foot malformations. The lesion relapsed after surgical excision in one case. Histology showed features of a well-developed and normal nail plate and matrix. A transmission electron microscope study was done in one case, showing typical aspects of onychocytes. The other nail was reproduced by a silicone replica technique and its superficial texture, shape and relationship with surrounding tissue were analysed by scanning electron microscopy.