Acanthosis nigricans


  • Multiple forms, but malignant acanthosis nigricans is most important
    • Most commonly associated with colonic adenocarcinoma, gastric cancer, ovarian cancer
    • Also associated with other dermal manifestations of internal cancers
  • Associated with GI and GU malignancies, which may have concomitant weight loss
  • Non malignant form may be associated with endocrine abnormalities, such as insulin resistance

Clinical Features

Malignant acanthosis nigricans secondary to ovarian cancer
  • Hyperpigmented, velvety
  • Plaques
  • Most commonly intertriginous areas, posterior neck
  • May have concurrent acrochordons, skin tags

Differential Diagnosis

Dark raised skin lesions



  • Red flags for malignant acanthosis nigricans:
    • Oral involvement (up to 50%)
    • Rapid appearance of lesions
    • Extensive involvement
    • Older adult
    • Unexplained weight loss
    • Lesions in atypical sites such as palms/soles, mucous membranes



External Links

See Also


  • Schwarzenberger K, Callen JP. Chapter 53: Dermatologic manifestations in patients with systemic disease. In: Bolognia JL,‎ Schaffer JV,‎ Cerroni L, eds. Dermatology. 4th ed. Philadelphia, PA: Elsevier; 2017:820.