About Merkel Cell Carcinoma
Merkel cell carcinoma (MCC) is a rare neuroendocrine skin cancer with aggressive behavior and high recurrence rates. It arises from Merkel cells, specialized mechanoreceptors in the basal layer of the epidermis. MCC is associated with two distinct etiologic pathways: Merkel cell polyomavirus (MCPyV) integration (80% of cases) and ultraviolet radiation-induced DNA damage (virus-negative MCC, which typically has very high mutational burden).
MCC typically presents as a rapidly growing, painless, dome-shaped nodule on sun-exposed skin. The mnemonic AEIOU describes its features: Asymptomatic, Expanding rapidly, Immune suppression, Older age, UV-exposed skin. Despite its small primary tumor size, MCC has a high propensity for lymph node metastasis and distant spread. Treatment involves wide surgical excision with sentinel lymph node biopsy, often followed by radiation therapy. For advanced or metastatic MCC, checkpoint immunotherapy (avelumab or pembrolizumab) has shown remarkable response rates, transforming outcomes for this disease.
Common Symptoms of Merkel Cell Carcinoma
Recognizing the signs of Merkel Cell Carcinoma early can lead to faster diagnosis and better outcomes. Symptoms may vary in severity from person to person. If you or a loved one are experiencing any of the following, consider speaking with a specialist.
- A firm, painless, dome-shaped nodule on the skin
- Rapidly growing skin lesion, often red, blue, or purple
- Usually appears on sun-exposed areas (head, neck, arms)
- Nodule may be shiny and flesh-colored to red
- Rarely causes pain or itching in early stages
- May be mistaken for a cyst or other benign skin growth
Who Merkel Cell Carcinoma Affects
Primarily affects older adults (median age at diagnosis ~75-80 years), with strong association with chronic sun exposure and fair skin. Significantly more common in immunosuppressed individuals (organ transplant recipients, HIV patients, chronic lymphocytic leukemia patients). About 3-5 times more common in men than women. Merkel cell polyomavirus (MCPyV) is found in ~80% of tumors.
Find Your Next Step
FDA-Approved Treatments for Merkel Cell Carcinoma
There are currently 3 FDA-approved medications for Merkel Cell Carcinoma. These therapies represent the current standard of care and may be used alongside or compared against investigational treatments in active clinical trials.
Source: openFDA drug labeling data. This list may not include all treatments. Always consult your doctor.
Help Paying for Merkel Cell Carcinoma Treatment
Charity funds and drugmaker programs for Merkel Cell Carcinoma, checked at the source.
No charity fund for this condition is open right now. Funds reopen when they receive new donations; the foundations let you sign up to be told when one opens.
Side Effect Explorer
Real-world side effect reports from the FDA Adverse Event Reporting System (FAERS). Includes both FDA-approved drugs and investigational therapies from active clinical trials. Click any drug to see what patients reported.
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Diagnosis and Testing
About 70 to 80% of US cases are driven by clonally integrated Merkel cell polyomavirus and the rest by UV damage; no inherited gene test has a diagnostic role.
Trusted Merkel Cell Carcinoma Resources
Reputable organizations and medical references for learning more about Merkel Cell Carcinoma, including disease registries, foundation resources, and clinical guidelines.