Health Library

Mohs Micrographic Surgery

Definition

This procedure is used to remove skin cancer that affects the face and other sensitive areas. The doctor removes the cancer layer by layer, examining the tissue under a microscope until only healthy tissue remains.

Basal Cell Carcinoma
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Reasons for Procedure

This surgery is most often used to treat basal and squamous cell carcinomas and other more rare skin cancers that:

  • Appear on the face (including eye lids, lips), scalp, ears, neck, shins, hands, fingers, feet, toes, and genitals
  • Were previously treated and came back
  • Occur near scar tissue
  • Are large
  • Have poorly-defined edges
  • Are growing rapidly

This surgery is an effective and precise way to treat basal and squamous cell skin cancers. It offers a good chance for complete removal of the cancer, while sparing normal tissue.

Possible Complications

Complications are rare, but no procedure is completely free of risk. If you are planning to have Mohs surgery, your doctor will review a list of possible complications, which may include:

  • Bleeding
  • Scarring
  • Reaction to the local anesthesia
  • Infection
  • Damage to nerve endings (temporary or permanent numbness or weakness)
  • Itching or shooting-pain sensations

Before your procedure, talk to your doctor about ways to manage factors that may increase your risk of complications such as:

  • Smoking
  • Drinking
  • Taking blood thinners
  • Chronic disease such as diabetes or obesity

What to Expect

Prior to Procedure

In the time leading up to the procedure:

  • Discuss with your doctor any allergies or medical problems that you have.
  • You will most likely be able to continue taking your medicines. Tell your doctor if you are taking any blood thinning medicines.
  • Arrange for a ride home and for help at home.
  • Eat normally the day of the procedure.

Anesthesia

Local anesthesia will be used. You will not feel pain. You will be awake during the procedure.

Description of Procedure

The area will be cleansed with antiseptic. A local anesthetic will be injected into the area. Using a small scalpel, the doctor will remove the top visible portion of the cancer. Next, the doctor will remove another, deeper layer. The layer will be divided into sections. Each section will be color coded. This will allow the doctor to know exactly where the layer was in the skin.

These sections will be frozen and examined under a microscope for remaining cancer cells. If cancer is found at the edges of the removed layer, the doctor will go back to the precise section. Additional layers will be removed until all areas are cancer free. For larger wound areas, the doctor will close the wound with stitches, skin flap, or a skin graft procedure. Small, shallow wounds may heal without stitches.

How Long Will It Take?

The surgery will go quickly. You will have to wait while the doctor examines the tissue microscopically. In some cases, this procedure can last for several hours.

How Much Will It Hurt?

You should have minimal discomfort during the procedure. There will be some minor pain during recovery. You may be given pain medicine.

Post-procedure Care

At the Care Center

During your stay, the hospital staff will take steps to reduce your chance of infection such as:

  • Washing their hands
  • Wearing gloves or masks
  • Keeping your incisions covered

There are also steps you can take to reduce your chances of infection such as:

  • Washing your hands often and reminding visitors and healthcare providers to do the same
  • Reminding your healthcare providers to wear gloves or masks
  • Not allowing others to touch your incisions

After the procedure, you may be given pain medicine and an antibiotic. You will be able to leave the same day.

At Home

When you return home, do the following to help ensure a smooth recovery:

  • Keep the area clean, dry, and protected. Follow your doctor’s instructions for caring for the wound.
  • Ask your doctor about when it is safe to shower, bathe, or soak in water.
  • For pain relief, take over-the-counter pain medicine, such as acetaminophen .
  • Be sure to attend any follow-up visits. Your doctor will monitor your condition.
  • Keep in mind that it is normal for a scar to form. The appearance may improve over time.
  • Take steps to prevent skin cancer:
    • Use sunscreens with a sun protection factor (SPF) of at least 15.
    • Protect your skin from the sun. For example, wear a shirt, wide brimmed hat, and sunglasses.
    • Regularly check your skin for changes.

Call Your Doctor

After arriving home, contact your doctor if any of the following occurs:

  • Bleeding or other drainage
  • Increased pain
  • Redness, warmth, tenderness, or swelling at the incision site
  • Signs of infection, including fever and chills

If you think you have an emergency, call for medical help right away.

Resources

American College of Mohs Surgery
http://www.mohscollege.org/

American Society for Mohs Surgery
http://www.mohssurgery.org/

Canadian Resources

Canadian Association of Mohs Surgeons
http://www.mohssurgery.ca/cams.html

Canadian Cancer Society
http://www.cancer.ca/

References

Narayanan K, Hadid OH, Barnes EA. Mohs micrographic surgery versus surgical excision for periocular basal cell carcinoma. The Cochrane Collaboration website. Available at: http://www.cochrane.org/reviews/en/ab007041.html. Published April 15, 2009. Accessed February 2, 2010.

6/6/2011 DynaMed's Systematic Literature Surveillance http://www.ebscohost.com/dynamed : Mills E, Eyawo O, Lockhart I, Kelly S, Wu P, Ebbert JO. Smoking cessation reduces postoperative complications: a systematic review and meta-analysis. Am J Med. 2011;124(2):144-154.e8.