Merkel cell carcinoma


The following tests are done to diagnose Merkel cell carcinoma:

  • Physical exam. The doctor will examine your moles, freckles, skin pigmentation and other abnormalities on your skin.
  • Skin biopsy. The doctor will remove a sample of suspicious skin tissue for examination under a microscope in the laboratory to look for any cancer cells.

Determining the extent of cancer

Stage of Merkel cell carcinoma may be determined using the following tests:

  • Sentinel node biopsy. This technique injects a dye near the cancer which will run through the lymphatic system to check if the cancer has reached the lymph nodes.
  • Imaging tests. Chest X-ray and a CT scan of your chest and abdomen will be suggested by the doctor to determine if the cancer has spread to other organs. Another test which may be done is Positron Emission Tomography (PET) scan or an octreotide scan. During PET scan, a radioactive tracer is injected to check if the cancer cells have spread.

Merkel cell carcinoma may be staged from 0 to IV. The lowest number indicates that the cancer is localized only in outer layer of skin (epidermis). If it has reached stage IV, it means that cancer has become advanced and has spread to other parts of the body (metastasis).


These are the treatment options for Merkel cell carcinoma:

  • Surgery. The tumor and some healthy skin around it may be surgically removed, including the lymph nodes if it has been found that the cancer has spread into them. A procedure called Mohs surgery may also be done by cutting the cancer using a scalpel. This technique analyzes a thin layer of skin under the microscope to check if cancer cells are present. If cancer cells are still present, the procedure is continuously done to remove them until cancer cells are no longer detected and the border of skin is tumor-free.
  • Radiation therapy. A strong energy beam is used though X-rays and protons to kill cancer cells. The patient will lie down on the table and a large machine is navigated around the patient to target a specific area that is affected in the body. Radiation may be used after surgery to kill the remaining cancer cells after tumor removal. It may also be used alone to kill cancer cells that has spread to other areas of the body.
  • Immunotherapy. Uses the body’s own immune system to kill cancer cells. It is commonly used to target Merkel cell carcinoma that has metastasized to other parts of the body.
  • Chemotherapy. Uses medications administered orally or intravenously, or both, to kill cancer cells. It is uncommon to use chemotherapy in Merkel cell carcinoma but it may be used if the cancer has reached the lymph nodes or other body organs.