Becker's melanosis: an organoid hamartoma.

: Herein we have reported the histologic findings in two cases of Becker's melanosis. In one patient the lesion showed hyperplasia or hair muscles and in the other patient the lesion was associated with an underlying neurofibroma. The proliferative changes seen in the epidermis and dermis in Becker's melanosis can best be explained by the concept of an organoid hamartoma with involvement of the epidermis, pilar structures, and some other dermal components. The localization of the plexiform neurofibroma within the Becker's nervus is a unique observation. It may fall within the spectrum of an organoid hamartoma or it may only represent a chance occurrence.