Merkel cell carcinoma is a rare, rapidly spreading skin cancer that tends to affect older White people.
Merkel cells are normal cells in the epidermis (the outer layer of the skin). These cells mostly function as touch receptors and they produce certain hormones. Merkel cell carcinoma arises from uncontrolled growth of cells in the skin that share some characteristics with normal Merkel cells.
Merkel cell carcinoma is diagnosed at an average age of 75 years. It also affects younger people whose immune system is weakened. Sun exposure increases the risk, as does having another cancer (such as melanoma or chronic lymphocytic leukemia). The Merkel cell polyomavirus may be a contributory factor.
This cancer commonly spreads to the lymph nodes.
Symptoms of Merkel Cell Carcinoma
The cancer is typically a firm, shiny, flesh-colored or bluish red bump. The bumps tend to grow rapidly without causing pain or tenderness.
Although Merkel cell carcinoma can affect any part of the skin, it is most common on skin that has been chronically exposed to sunlight (for example, the face and arms).
Diagnosis of Merkel Cell Carcinoma
Biopsy
A biopsy is done to confirm the diagnosis of Merkel cell carcinoma. During this procedure, a small piece of skin is removed and examined under a microscope.
In most people, the cancer has already spread by the time the diagnosis has been made, so the prognosis for Merkel cell carcinoma is poor.
Treatment of Merkel Cell Carcinoma
Surgical removal of the tumor
Usually radiation therapy and removal of lymph nodes
Sometimes chemotherapy
Treatment of Merkel cell carcinoma usually involves surgery to remove the tumor, often followed by radiation therapy, removal or biopsy of lymph nodes, or both.
If cancer has spread or returns, chemotherapy may be recommended.
Prevention of Merkel Cell Carcinoma
Because Merkel cell carcinoma is caused by sun exposure, people can help prevent this cancer by doing the following, starting in early childhood:
Avoiding the sun: For example, seeking shade, minimizing outdoor activities between 10 AM and 4 PM (when the sun’s rays are strongest), and avoiding sunbathing and the use of tanning beds
Wearing protective clothing: For example, long-sleeved shirts, pants, and broad-brimmed hats
Using sunscreen: At least sun protection factor (SPF) 30 with UVA and UVB protection used as directed and reapplied every 2 hours and after swimming or sweating but not used to prolong sun exposure
More Information
The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
Merkelcell.org: A resource to help people find access to Merkel cell specialists and other patient resources
American Cancer Society: Merkel Cell Skin Cancer: Information about Merkel cell carcinoma, including detection, prevention, treatment options, and other resources
The Skin Cancer Foundation: Merkel Cell Carcinoma Overview: Information about Merkel cell carcinoma, including detection, prevention, treatment options, and other resources
