Diagnosis
Merkel cell carcinoma diagnosis often starts with an exam. A healthcare professional may look at your skin and remove a sample of cells for testing. This skin cancer may be hard to diagnose because it may look like other skin growths.
Physical exam
During a physical exam, a healthcare professional looks at your skin for moles, freckles and other growths.
Biopsy
A biopsy is a procedure to remove a sample of tissue for testing in a lab. For Merkel cell carcinoma, a healthcare professional may use a tool to cut away some of the concerning skin. Other ways to do a skin biopsy involve using a shaving tool or a circular cutting tool to get some of the skin. The sample is tested in a lab to see if it is cancer.
Tests for cancer that spreads
Your healthcare professional may use other tests to find out whether the cancer has spread beyond your skin. These other tests may include:
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Sentinel node biopsy. A sentinel node biopsy is a procedure to see whether cancer has spread to the lymph nodes. This procedure involves putting a dye into the skin near the cancer. The dye then flows through the lymphatic system to the lymph nodes.
The first lymph nodes that get the dye are called the sentinel nodes. A healthcare professional removes these lymph nodes and looks for cancer cells under a microscope.
- Imaging tests. Imaging tests used to look for signs that the cancer has spread include a chest X-ray, a CT scan of the chest and belly, and a positron emission tomography scan, also called a PET scan.
More Information
Treatment
Treatment for Merkel cell carcinoma most often involves surgery to remove the cancer. If the cancer has spread beyond the skin, treatment may involve medicines or radiation.
Surgery
A surgeon removes the cancer along with a border of skin that doesn't have cancer. For cancer that has spread to lymph nodes near the skin cancer, the surgeon removes those lymph nodes. This is called a lymph node dissection.
Surgery most often involves a scalpel to cut away the cancer. Sometimes, a surgeon may use a procedure called Mohs surgery.
Mohs surgery involves cutting away thin layers of skin. The surgeon uses a microscope to look at each layer for cancer. The process keeps going until there's no more cancer. The goal of Mohs surgery is to remove all the cancer without harming the healthy skin around it.
Radiation therapy
Radiation therapy treats cancer with powerful energy beams. For Merkel cell carcinoma, a healthcare professional may use radiation therapy after surgery to destroy cancer cells that remain. Radiation may be the only treatment for people who don't want to have surgery. Radiation also can treat cancer that has spread.
Immunotherapy
Immunotherapy for cancer is a treatment with medicine that helps the body's immune system kill cancer cells. The immune system fights off diseases by attacking germs and other cells that shouldn't be in the body. Cancer cells survive by hiding from the immune system. Immunotherapy helps the immune system cells find and kill the cancer cells.
Most often, immunotherapy treats Merkel cell carcinoma that comes back after treatment or spreads to other areas of the body.
Chemotherapy
Chemotherapy treats cancer with strong medicines. Healthcare professionals don't often use chemotherapy to treat Merkel cell carcinoma. But your healthcare team may suggest it if your Merkel cell carcinoma spreads to your lymph nodes or other organs, or if it returns after treatment.
Clinical trials
Explore Mayo Clinic studies testing new treatments, interventions and tests as a means to prevent, detect, treat or manage this condition.
Preparing for your appointment
If you have a mole, freckle or bump on your skin that concerns you, start by making an appointment with a healthcare professional. For skin cancer, you'll likely be sent to a skin specialist, called a dermatologist.
Here's some information to help you get ready for your appointment.
What you can do
Ask a family member or friend to go with you to help you remember the information you get.
Make a list of:
- Your symptoms and when they began. Include any that don't seem linked to the reason you made the appointment.
- Key personal information. Include major stresses or recent life changes.
- Medical information. Include other conditions you have or conditions that run in your family.
- All medicines, vitamins or supplements that you take. Include the dosages.
- Questions to ask your healthcare professional.
For Merkel cell carcinoma, questions might include:
- What is likely causing my symptoms or condition?
- Are there other possible causes for my symptoms or condition?
- What tests do I need?
- What treatments are there?
- I have other health conditions. How can I best manage them together?
- Are there brochures or other printed material I can have? What websites do you suggest?
Be sure to ask all the questions you have.
What to expect from your doctor
Your healthcare team is likely to ask you questions, such as:
- How have your symptoms changed over time?
- Does anything make your symptoms better?
- Have you spent a lot of time in the sun, or have you used tanning beds?
- Do you have a history of other skin conditions, such as skin cancer or psoriasis? What treatments have you used for those conditions?
- Have you been diagnosed with any immune system conditions? If so, what treatments have you used?
Jan. 10, 2025