common seborrhoeic keratosis

Last reviewed 01/2018

The common form of seborrhoeic keratosis has characteristic features:

  • macroscopically, mushroom-shaped
  • histologically:
    • hyperplastic epidermis overhanging surrounding skin
    • uniform basal cell overgrowth
    • keratin cysts
    • melanocytes may be present in large numbers giving rise to the variable pigmentation