Merkel cell carcinoma: An update and review: Pathogenesis, diagnosis, and staging

J Am Acad Dermatol. 2018 Mar;78(3):433-442. doi: 10.1016/j.jaad.2017.12.001. Epub 2017 Dec 9.


Merkel cell carcinoma (MCC) is an uncommon primary cutaneous neuroendocrine cancer. It most commonly presents as an indurated plaque or nodule on sun-damaged skin in elderly patients and is characterized by high rates of local recurrence and nodal metastasis. Survival at 5 years is 51% for local disease and as low as 14% for distant disease, which underscores the aggressive nature of this tumor and challenges in management. Advances in immunology and molecular genetics have broadened our understanding of the pathophysiology of MCC and expanded our therapeutic arsenal. With this comprehensive review, we provide an update of MCC epidemiology, pathogenesis, clinical presentation, diagnostic evaluation and prognostic markers. The second article in this continuing medical education series explores the evolving landscape in MCC management.

Keywords: Merkel cell carcinoma; Merkel cell polyomavirus; Merkel cells; cytokeratin-20.

Publication types

  • Review

MeSH terms

  • Carcinoma, Merkel Cell / diagnosis*
  • Carcinoma, Merkel Cell / epidemiology
  • Carcinoma, Merkel Cell / secondary*
  • Humans
  • Neoplasm Staging
  • Prognosis
  • Skin Neoplasms / diagnosis*
  • Skin Neoplasms / epidemiology
  • Skin Neoplasms / pathology*