Dermatosis Papulosa Nigra Workup

Updated: Aug 07, 2017
  • Author: Mehran Nowfar-Rad, MD; Chief Editor: Dirk M Elston, MD  more...
  • Print
Workup

Histologic Findings

Lesions of dermatosis papulosa nigra have the histologic appearance of seborrheic keratoses; they display hyperkeratosis, irregular acanthosis, keratin-filled invaginations of the epidermis (horn cysts), and marked hyperpigmentation of the basal layer. Although most lesions are of the acanthotic type and show thick interwoven tracts of epidermal cells, they may have a reticulated pattern in which the tracts consist of a double row of basaloid cells.