Mohs Micrographic Surgery
This procedure is used to remove skin cancer that affects the face and other sensitive areas. The cancer is removed layer by layer. The tissue is examined under a microscope until only healthy tissue remains.
Basal Cell Carcinoma
Reasons for Procedure
- Appear on the face (including the eye lids and 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.
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:
- Reaction to the local anesthesia
- 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:
- 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.
- Talk to your doctor if you take any medications, herbs, or supplements. You may need to stop taking some medications up to 1 week before the procedure.
- Arrange for a ride home and for help at home.
- Eat normally the day of the procedure.
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 top visible portion of the cancer will be removed. Next, another, deeper layer will be removed. 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 wound will be closed with stitches, a 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 tissue is examined 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 medication.
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 medication and an antibiotic. You will be able to leave the same day.
When you return home, do the following to help ensure a smooth recovery:
- 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 30.
- 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 emergency medical services right away.
American College of Mohs Surgery
American Society for Mohs Surgery
Canadian Association of Mohs Surgeons
Canadian Cancer Society
Sunscreen FAQs. American Academy of Dermatology website. Available at: https://www.aad.org/media-resources/stats-and-facts/prevention-and-care/sunscreens. Accessed February 25, 2015.
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.
Last reviewed February 2015 by Marcin Chwistek, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.