Becker nevus of the face with asymmetrical growth of beard hair

Becker’s nevus (BN) is a fairly common cutaneous hamartoma clinically characterized by a patchy hyperpigmentation with irregular outline and hypertrichosis. Usually manifesting in late childhood or adolescence, it affects mainly men in a geographical configuration, having a predilection for the proximal upper extremities and the upper half of the trunk. Apart from few reports of lower limb involvement, the presence of BNs on other sites has to be considered exceptional. We describe the case of a 14-year-old girl was referred to our clinic with the suspect diagnosis of hirsutism in a patient affected by polycystic ovaries. She complained of unwanted hair growth on his right cheek since puberty, with only a light down on the other side of the face. To the best of our knowledge facial localization of BN has been just described in literature in only five cases, all being seen in males, presenting with an unius lateris macula and hypertrichosis during puberty. The present case, because of the involvement of the face, as asymmetrical growth of beard hair in a woman in absence of any apparent hormonal influences, represents a unique report in literature, thus bringing into question the possible relationship between BN and androgen metabolism.