Acanthosis nigricans


  • Multiple forms, but malignant acanthosis nigricans is most important
  • Clinically indistinguishable from benign form

Clinical Features

  • Hyperpigmented, velvety
  • Plaques
  • Most commonly intertriginous areas, posterior neck
  • May have concurrent acrochordons, skin tags

Malignant Acanthosis Nigricans[1]

Malignant acanthosis nigricans secondary to ovarian cancer
  • Associated with other dermal manifestations of internal cancers
  • Most commonly associated with colonic adenocarcinoma, gastric cancer, ovarian cancer
  • Red flags:
    • Up to 50% of malignant acanthosis nigricans have oral involvement
    • Rapid appearance of lesions
    • Extensive involvement
    • Older adult
    • Unexplained weight loss
    • Lesions in atypical sites such as palms/soles, mucous membranes

See Also


  1. Miller JH et al. Acanthosis Nigricans Clinical Presentation. eMedicine. Dec 3, 2015.