About Your Mohs Surgery

This information describes what to expect before, during, and after your Mohs surgery at Memorial Sloan Kettering (MSK).

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About Mohs Surgery

Mohs surgery is a type of surgery to treat skin cancer. It’s done using a special technique to remove all of the skin cancer but save the healthy tissue. This helps limit scarring.

Mohs surgery is the most effective treatment for skin cancer. It’s often used to treat skin cancers that:

  • Are on areas where keeping appearance and function are important
  • Have come back after being removed
  • Have edges that are uneven
  • Are large
  • Grow quickly

During your surgery, a layer of tissue will be removed from your skin and checked for cancer cells using a microscope. If there are cancer cells, more layers will be removed and checked for cancer cells. This will continue until all of the skin cancer has been removed and the margins are clear.

Mohs is an outpatient procedure, which means you don’t need to be admitted to the hospital. You won’t get general anesthesia (medication to make you sleep) during your surgery. You will get local anesthetic (medication to make an area of your body numb).

Risks of Mohs surgery

Talk with your healthcare provider about your risks with Mohs surgery. Possible risks include:

  • Pain or tenderness at the surgery site
  • Infection
  • Bleeding from the surgery site
  • Scarring
  • Slow or poor wound healing
  • Numbness at the surgery site
  • The wound splitting open where the incision (surgical cut) was made. This is only a risk if your wound is closed with sutures (stitches).
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Before Your Mohs Surgery

You will get information about how to prepare for your surgery. You will have time to review it and ask questions. If you’re having a plastic surgeon close your wound, you will also get more information.

Your healthcare provider will review your medications and health history.

If you develop any illness (fever, cold, sore throat, or flu) or are hospitalized before your surgery, call your healthcare provider’s office.

Depending on how many layers of tissue need to be removed, you may be at MSK for several hours. We recommend that you eat breakfast and bring lunch or snacks with you on the day of your appointment. There will be a refrigerator where you can store your food, if needed.

If you’d like to bring a friend or family member with you on the day of your surgery or if you have any questions, call your healthcare provider’s office.

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The Day of Your Mohs Surgery

The length of your surgery depends on how many layers of tissue are removed. Some people may need to spend the whole day at MSK.

During your Mohs surgery

First, you will get an injection (shot) of local anesthesia to numb the surgery site. Once the area is numb, the cancerous tissue and a thin layer of surrounding tissue will be removed. A bandage will be placed on your wound.

After your wound is bandaged, you will either be taken to a waiting area or stay in the procedure room to wait. While you wait, you can relax and eat light snacks or your lunch.

The removed tissue will be processed and examined in the lab. If there are cancer cells at the border (edge) of the tissue, another layer of tissue will need to be removed.

These steps will be repeated until there are no more cancer cells found at the borders of the tissue that is removed.

Closing your wound

After all the cancer is removed, you and your doctor will discuss the best way for your wound to heal and close. Examples include:

  • Allowing the wound to heal by itself.
  • Suturing the wound closed.
  • Creating a skin graft or flap to close the wound. A skin graft or flap is tissue that’s taken from one part of your body and moved to another area that needs to be covered.
  • Creating a porcine (por-sine) xenograft (zee-noh-graft) to close the wound. A porcine xenograft is tissue that’s taken from a pig and moved to the area that needs to be covered on your body.
  • Having a plastic surgeon close the wound. If you need to have a plastic surgeon close your wound, this needs to be planned ahead of time.

Before you leave MSK, you will get instructions about how to care for your wound at home. You will also be told when you need to come back to MSK for your follow-up appointment.

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After Your Mohs Surgery

You will be able to go home right after your procedure.

  • You may have pain after your surgery. If you have pain, try taking extra strength acetaminophen (such as Tylenol® Extra Strength).
    • If you’re allergic to acetaminophen or can’t take it due to a medical condition, ask your healthcare provider what you can take instead.
    • Don’t take aspirin or nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Motrin®, Advil®) and naproxen (Aleve®) unless your healthcare provider says it’s okay. These medications can cause bleeding.
  • You can also hold an ice pack over your wound to reduce pain and swelling. Hold the ice pack on your wound for 15 to 20 minutes every hour or follow the instructions your healthcare provider gives you.
  • If you have sutures, do not lift anything greater than 15 pounds. They will be removed during a follow-up appointment.
  • Do not exercise for two weeks after your surgery.
  • Do not travel on a plane.
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