Nevoid hyperkeratosis of the nipple and the areola.

A 25-year-old woman presented to our dermatology unit with progressive diffuse thickening of the both areolas. A skin biopsy was taken from the right areola showing irregular filiform acanthosis with elongation and anastomosis of rete ridges, irregular orthokeratotic hyperkeratosis, pseudocyst formation, and hyperpigmentation of the basal layer. The cause of nevoid hyperkeratosis of the nipple and areola is unknown.