Merkel cell carcinoma is a rare skin cancer that typically develops in older individuals. A fast growing skin cancer, merkel cell carcinoma can metastasize to other parts of the body. For this reason, merkel cell carcinoma is more dangerous than other skin cancers. Merkel cell carcinoma originates from the outermost layer of the skin (epidermis), in a cell known as the Merkel cell (1).
Merkel cell carcinomas usually begin as either a skin colored nodule, or a discolored nodule, appearing in shades of red, purple, or blue (1). These nodules may appear firm, dome-shaped, or raised. While initially painless, these nodules are fast growing and begin to spread to other areas of the body. Nodules generally appear on areas exposed to sunlight, such as the face, head, or neck. Over time, these nodules may start to appear in areas not exposed to sun contact. As the cancer spreads to other parts of the body, the lymph nodes may swell. Pain and fatigue may result as the cancer spreads.
Merkel cell carcinomas result from overexposure to UV radiation from the sun. Individuals exposed to artificial sunlight are also at risk, as are those with weakened immune systems. The use of an immunosuppressant, a history of cancer, or being over fifty years of age can also contribute to development of merkel cell carcinomas. Typically, white males are more at risk for development of merkel cell carcinoma (2).
Since merkel cell carcinomas are fast spreading, early detection is important. A physical exam is an excellent start; however some merkel cell carcinomas may avoid detection. A full-body skin scan or more thorough exams from a dermatologist may increase the chance of detection. If a lump is found, a biopsy of the nodule can be taken to determine if it is Merkel cell carcinoma.
Treatment depends on severity of the cancer. If the tumor has not metastasized, surgical treatment is an option. Use of Mohs surgery has a high success rate. For tumors that have metastasized, chemotherapy or radiation may be a more viable option. Most importantly, merkel cell carcinoma is rare. Still, if you notice an abnormal lump, contact your physician.