This rare skin cancer often looks harmless. Many people mistake it for a pimple, bug bite, or cyst. If you see a lump or hardened patch on your skin that looks like any pictures on this page, you should immediately make an appointment to see a dermatologist.
This appointment is especially important if you have:
- Fair skin and are 50 years of age or older.
- A disease that weakens your immune system, such as HIV or chronic lymphocytic leukemia (a cancer of the blood and bone marrow).
- Received an organ transplant.
- Had Merkel cell carcinoma (MCC) or another skin cancer.
Merkel cell carcinoma: What it looks like
MCC often appears on skin that has had lots of sun exposure. The MCC tumor tends to:
- Feel firm.
- Grow quickly (in a few weeks or months).
- Have one color, either red, pink, blue, or violet.
MCC also can appear as a rough, hardened patch of skin. This patch tends to form on the trunk of the body.
Merkel cell carcinoma: This rare skin cancer most commonly looks like a shiny, dome-shaped growth that has visible blood vessels.
Merkel cell carcinoma: Symptoms
People diagnosed with MCC often say that the lump or patch was painless.
Merkel cell carcinoma: Where it appears on the body
This rare skin cancer can develop anywhere on the skin. Most MCCs, however, appear on skin that has received lots of sun exposure. About half of MCCs develop on the head or neck, with many of these forming on the eyelid. Other places that MCC tends to develop are the legs, arms, feet, buttocks, and genitals.
One of the greatest risk factors for MCC is age. Most MCCs develop in people who are 50 years of age or older. Other risk factors for MCC also increase the likelihood of developing this rare skin cancer. You will find the risk factors at Merkel cell carcinoma: Who gets and causes.
Learn more about Merkel cell carcinoma:
Images used with permission of Journal of the American Academy of Dermatology: 1 J Am Acad Dermatol. 2011; 65:983-90
Akhtar S, Oza KK, Wright J. “Merkel cell carcinoma: report of 10 cases and review of the literature.” J Am Acad Dermatol 2000 Nov; 43(5 Pt 1):755-67.
Becker JC. “Merkel cell carcinoma.” Ann Oncol 2010; 21(suppl 7)vii81-5.
Gao L. “Merkel cell carcinoma: Tips and advancements in management.” Educational session presented at the 2013 American Academy of Dermatology Annual Meeting: Miami. Mar 2013.
Heath M, Jaimes N, Lemos BD, et al. “Clinical characteristics of Merkel cell carcinoma at diagnosis in 195 patients: the AEIOU features.” J Am Acad Dermatol 2008; 58:375-81.
Pape E, Rezvov N, Penel N, et al. “Radiotherapy alone for Merkel cell carcinoma: a comparative and retrospective study of 25 patients.” J Am Acad Dermatol 2011; 65:983-90.