Neuroendocrine carcinoma of the skin, commonly referred to as Merkel cell carcinoma, is a relatively uncommon form of skin cancer that typically affects the head, neck, and face. It is a fast-growing carcinoma that can metastasize to other parts of the body. Merkel cell carcinoma is most common in older adults who have a long history of sun exposure or a weakened immune system.
Symptoms of Merkel Cell Carcinoma
An initial symptom of Merkel cell carcinoma is a painless skin nodule that may be flesh-colored, purple, red, or blue. The affected area may bleed easily even after a minor trauma. This type of skin cancer affects the Merkel cells that are located near the nerve endings in the top layer of skin called the epidermis. The cancer causes the Merkel cells to grow uncontrollably, especially in areas exposed to the sun.
Causes of Merkel Cell Carcinoma
The exact cause of Merkel cell carcinoma is not known. There is some evidence suggesting that it may be linked to a particular virus called Merkel cell polyomavirus. The virus is quite common, lives on the skin, and does not cause any particular symptoms. More research is needed to determine the role of the virus in the development of cancer since Merkel cell carcinoma is rare and the polyomavirus is so common.
Risk Factors for Merkel Cell Carcinoma
Since this type of carcinoma typically develops on sun-exposed areas of skin, excessive exposure to both artificial and natural sunlight appears to be a leading risk factor. Individuals with health conditions that weaken the immune system, who take immunosuppressant medications, or who have a history of other forms of skin cancer are also at higher risk. Merkel cell carcinoma is most prevalent in older adults and individuals with light-colored skin.
When to Seek Skin Cancer Treatment
Anyone noticing a bump, mole, or freckle that changes or becomes symptomatic over time should see a dermatologist or dermatology provider. Cancer treatments for Merkel cell carcinoma depend on whether the cancer affects areas other than the skin. Merkel cell carcinoma can metastasize quickly to nearby lymph nodes or organs, including the bones, lungs, brain, or liver. Merkel cell carcinoma can be fatal if it affects the functioning of these organs.