Merkel Cell Carcinoma Overview

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Merkel Cell Carcinoma

Merkel cell carcinoma is a rare form of cancer that is found most often on the parts of the body that have undergone sun exposure. It forms just beneath or on the skin and is most commonly found in people with a weakened immune system or who are older.

Other names for this cancer are neuroendrocrine carcinoma of the skin, Merkel cell cancer and trabecular cancer.


What is known about the causes is limited. This type of cancer begins in the Merkel cells, which are cells located at the base of the epidermis.

Risk Factors

There are a number of risk factors associated with Merkel cell cancer. They include having a weakened immune system, age (over 50), having a lighter skin color, exposure to artificial or natural sunlight and having a history of skin cancer.

Signs and Symptoms

One of the first signs of Merkel cell cancer is a tumor on the skin. This tumor will likely be fast-growing and painless. It can appear to be shiny and flesh-colored or even have tones of red, purple or blue.

A precautionary measure from the Mayo Clinic regarding the signs of Merkel cell cancer is to consult a doctor any time a bump, freckle or mole changes in color, size, shape or begins to bleed easily.


To diagnose Merkel cell cancer, a doctor may do any of several things. He may conduct a physical examination of the skin to check for the presence of moles, freckles and other skin growths. This examination can include checking them for irregularities and changes over time.

Another diagnostic tool that may be used is to perform a skin biopsy and to have a lab analyze it for cancer.

If skin cancer is present, a sentinel node biopsy, an x-ray or a CT scan may be ordered to help determine how far, if at all, the cancer has spread.


The treatments used for Merkel cell cancer are similar to the treatments used for other types of cancer. They include surgical removal of tumors, chemotherapy and radiation treatment. They may be used separately or in conjunction with one another. The decision is one made by both the treating physician and patient.


There are things that can be done to help prevent the development of Merkel cell carcinoma. These methods involve reducing the risks.

  • Use sunscreen often and liberally
  • Wear hats and sunglasses. Make sure sunglasses offer UV protection.
  • Avoid the sun in the peak hours of 10 a.m. to 4 p.m.
  • Regularly check your skin and track changes in moles, freckles and bumps.


Merkel Cell Carcinoma.

Merkel Cell Carcinoma. Mayo Clinic Staff. September 11, 2010.

Merkel Cell Carcinoma-Definition. National Cancer Institute.