Rare Nephrology News

Disease Profile

Merkel cell carcinoma

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

1-9 / 100 000

US Estimated

Europe Estimated

Age of onset




C44.3 C44.6 C44.7


Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

Merkel cell cancer; Merkle tumors; Carcinoma, merkel cell;


Endocrine Diseases; Rare Cancers; Skin Diseases


Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer. It usually develops as a single, painless, bump on sun-exposed skin. The bump may be skin-colored or red-violet, and tends to grow rapidly over weeks to months. It may spread quickly to surrounding tissues, nearby lymph nodes, or more distant parts of the body. Factors associated with developing MCC include increasing age, fair skin, a history of extensive sun exposure, chronic immune suppression, and the Merkel cell polyomavirus. This virus has been detected in about 80% of people with MCC.[1][2] Treatment may include surgery, radiation therapy, and/or chemotherapy. Treatment options and prognosis depend on the location(s) and size of the cancer, whether it has just been diagnosed or has come back (recurred), and how deeply it has grown into the skin.[1]


This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
100% of people have these symptoms
Merkel cell skin cancer
30%-79% of people have these symptoms
Cellular immunodeficiency
Chronic noninfectious lymphadenopathy
Cutaneous photosensitivity
Photosensitive skin
Photosensitive skin rashes
Sensitivity to sunlight
Skin photosensitivity
Sun sensitivity

[ more ]

Erythematous macule
Erythematous plaque
Regional abnormality of skin
Skin nodule
5%-29% of people have these symptoms
Basal cell carcinoma
Carcinoid tumor
Lymphoid leukemia
Multiple myeloma
Squamous cell carcinoma of the skin
1%-4% of people have these symptoms
Abnormal brain FDG positron emission tomography
Brain neoplasm
Neoplasm of the outer ear
Outer ear tumor


Cancer is caused by changes (mutations) in the DNA inside of cells.[3] These mutations cause the cells to grow and divide into new cells, when they should not. The mutations that cause MCC are not inherited from a parent, but occur by chance during a person's lifetime (they are acquired, or somatic mutations). In many cases, it is not known what directly causes these mutations to occur. However, several factors are thought to increase the risk for mutations to occur such as exposure to sunlight.[7331][2]

Merkel cell polyomavirus is frequently involved in the development of MCC and is present in about 80% of MCC tumors tested. While the majority of people have been exposed to this virus by adulthood, it appears that the virus does not cause any symptoms except in the very rare situations in which it leads to MCC.[2]

Other risk factors that have been associated with MCC include:[1][2]

  • being older than age 50
  • having fair skin
  • having a history of extensive sun exposure
  • having chronic immune suppression (e.g. organ transplantation or HIV)

Having one or more risk factors does not mean that a person will develop MCC. Most people with risk factors will not develop MCC.[1]


FDA-Approved Treatments

The medication(s) listed below have been approved by the Food and Drug Administration (FDA) as orphan products for treatment of this condition. Learn more orphan products.


Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Organizations Providing General Support

      Learn more

      These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

      Where to Start

      • The American Cancer Society provides detailed information about Merkel cell carcinoma. Click on the link to access this information.
      • DermNet NZ is an online resource about skin diseases developed by the New Zealand Dermatological Society Incorporated. DermNet NZ provides information about this condition.
      • The Merck Manual provides information on this condition for patients and caregivers.
      • The National Cancer Institute provides the most current information on cancer for patients, health professionals, and the general public.
      • SkinCancerNet is a comprehensive online skin cancer information resource developed by the American Academy of Dermatology. Click on the link to view information on Merkel cell carcinoma.

        In-Depth Information

        • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
        • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
        • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
        • PubMed is a searchable database of medical literature and lists journal articles that discuss Merkel cell carcinoma. Click on the link to view a sample search on this topic.


          1. General Information About Merkel Cell carcinoma. National Cancer Institute. July 22, 2016; https://www.cancer.gov/types/skin/patient/merkel-cell-treatment-pdq.
          2. Causes of Merkel cell carcinoma. merkelcell.org. February, 2017; https://merkelcell.org/about-mcc/causes-of-merkel-cell-carcinoma/.
          3. What Causes Merkel Cell Carcinoma?. American Cancer Society. April 13, 2015; https://www.cancer.org/cancer/merkel-cell-skin-cancer/causes-risks-prevention/causes.html.

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