Benefits and Risks of Mohs Surgery

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Mohs micrographic surgery is a highly effective treatment for skin cancer. But as with all medical procedures, there are benefits and risks to this surgery. Understanding Mohs surgery benefits and risks will help you have a good discussion with your doctor about whether you are a good candidate for this procedure. 

Mohs Surgery Benefits 

Dr. Frederic Mohs developed the technique that became known as Mohs surgery in the 1930s. Over the years, the process has been refined and now is considered the most effective treatment for many basal cell carcinomas and squamous cell carcinomas. (Mohs surgery may also be used to treat melanoma.) The use of this procedure has ballooned in recent years, in large part due to these benefits: 

  • Convenient. Mohs surgery is typically performed in a doctor’s office or local surgery center. Patients are not “put to sleep” for surgery. Doctors use local anesthetic to numb the area they will be working on, so patients are awake and alert during the procedure. Because there is no general anesthetic, patients are allowed (and encouraged) to eat breakfast the day of surgery and snacks as needed on the day of surgery. In most cases, Mohs surgery requires just one day. 

  • Cost effective. Because Mohs surgery doesn’t require a fully equipped operating room, it’s less costly than more extensive surgeries. And because it’s such an effective cancer treatment, most patients will not need additional treatment. 

  • High cure rates. During Mohs surgery, the surgeon removes all visible cancer and a small layer of surrounding tissue. That layer of tissue is then carefully examined under a microscope for evidence of cancer cells. If any traces of cancer are apparent, the surgeon removes another thin layer of skin and checks it under the microscope. According to the Skin Cancer Foundation, the cure rate for Mohs surgery is approximately 99% for skin cancers that have not been treated before, and up to 94% for skin cancers that have recurred after previous treatment. 

  • Minimally invasive.  Because surgeons only remove a tiny bit of tissue at a time and stop to reassess before removing any more, you can be sure your doctor will only remove as much tissue as necessary. Healthy skin will be left undisturbed. Mohs surgery generally leaves the smallest scar possible. 

Mohs Surgery Risks  

All surgeries have risks. The risks of Mohs surgery include: 

  • Infection. Whenever the skin is opened or injured, there’s a chance of infection. Your medical team will work to reduce the risk by using sterilized tools and following strict protocols. You may also be instructed to take antibiotics prior to surgery, depending on your health history. 

  • Bleeding. Usually, very little blood is lost during Mohs surgery. People who take blood thinners (anticoagulant medicine) are at increased risk of bleeding, so doctors usually instruct patients to stop taking these meds a few days before surgery. Some over-the-counter medications and supplements, including ibuprofen, aspirin, naproxen, fish oil and vitamin E, also increase the risk of bleeding. Tell your physician about any medications and supplements you take and follow her recommendations regarding when to stop and resume intake. 

  • Nerve damage. Some nerves may be cut or damaged during Mohs surgery. Physicians do their best to prevent harm, but if the cancer encircles a nerve, it may be necessary to cut the nerve to remove the cancer. It is rare, but possible, to lose some sensitivity or movement after Mohs surgery. Nerve damage may be permanent or temporary. 

  • Poor wound healing. Most people who undergo Mohs have a good cosmetic outcome. But in some people, the wound doesn’t heal quickly, or it develops a red, raised scar called a keloid. (Keloids are more common in people of color). Additional treatment can minimize keloids. 

You might be a good candidate for Mohs surgery if… 

Your doctor may recommend Mohs surgery if: 

  • You have skin cancer on your eyelids, nose, lips, hands, ears, feet or genitals.

  • You only have one spot of skin cancer, or several spots located close together.

  • You have skin cancer that recurred after previous treatment.

  • You are comfortable with the time it takes for the results after removing each layer.  

Your healthcare provider can help you determine whether Mohs surgery is a good choice for you. 

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2019 Jul 12
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
  1. Mohs Micrographic Surgery. MedlinePlus, U.S. National Library of Medicine.
  2. Do You Know Mohs? What to Expect Before, During and After the Procedure. The Skin Cancer Foundation.
  3. Mohs Surgery. Mayo Clinic.
  4. What is Mohs Surgery? American College of Dermatology.
  5. Mohs Surgery: Risks/Benefits. Cleveland Clinic.
  6. Keloids. American College of Dermatology.