Mohs Surgery | Frequently Asked Questions

Question 1

What is Mohs surgery?

Accepted Answer

Mohs micrographic surgery is a precise technique for removing certain skin cancers. The surgeon removes thin layers of skin one at a time and examines each layer under a microscope right away. This continues until no cancer cells are seen. The process allows the doctor to remove the entire tumor while saving as much healthy skin as possible.

Question 2

Why is it called Mohs surgery?

Accepted Answer

The procedure is named after Dr. Frederic Mohs, a physician at the University of Wisconsin who developed the technique in the 1930s. His original method used a chemical paste to fix the tissue in place. Over the decades, the technique evolved into the modern form used today, which relies on fresh-tissue processing and same-day microscopic review.

Question 3

What types of skin cancer does Mohs surgery treat?

Accepted Answer

Mohs surgery is most commonly used for basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), the two most frequent skin cancers. It is also used for dermatofibrosarcoma protuberans (DFSP), melanoma in situ, and several other rare skin tumors. Your dermatologist will confirm whether your specific tumor type is best treated with Mohs.

Question 4

How is Mohs surgery different from regular excision?

Accepted Answer

Standard excision removes the visible tumor plus a margin of surrounding skin, then sends the tissue to a lab. Results take days, and only a small sample of the margin is checked. Mohs surgery, by contrast, processes the entire outer margin of every layer in real time, right in the office. This lets the surgeon verify that all cancer cells are gone before closing the wound, which is why cure rates are higher and less healthy tissue is removed.

Question 5

What is the cure rate for Mohs surgery?

Accepted Answer

Mohs surgery offers the highest cure rates of any treatment for the most common skin cancers. For a new (primary) basal cell carcinoma, the 5-year cure rate reaches up to 99%. For new squamous cell carcinoma it is approximately 97%. Even for tumors that have come back after previous treatment, Mohs cure rates remain around 94–95% for BCC and 90% for SCC.

Question 6

My biopsy already removed the visible spot. Do I still need surgery?

Accepted Answer

Yes. A shave or punch biopsy is a diagnostic tool. It is not designed to remove all of the cancer. Skin cancers often have microscopic roots that extend beyond what can be seen or felt. These invisible extensions are exactly what Mohs surgery is designed to find and eliminate. Skipping surgery because the spot looks gone is not recommended.

Question 7

Is Mohs surgery performed in a hospital?

Accepted Answer

Mohs surgery is almost always performed in an outpatient office or clinic setting, not a hospital. It uses local anesthesia, so you are awake and comfortable throughout. You will not need general anesthesia in the vast majority of cases, which means less risk and a faster recovery.

Question 8

How should I prepare for Mohs surgery?

Accepted Answer

Eat a normal breakfast or lunch before arriving. Do not fast unless you have been told otherwise. Wear comfortable, dark-colored clothing that can be easily rolled up or removed near the surgery site. Avoid wearing makeup, sunscreen, or lotions on the surgical area. Plan for a full day at the office, as timing can be unpredictable depending on how many stages are needed.

Question 9

Should I stop taking blood thinners before surgery?

Accepted Answer

Never stop prescription blood thinners, such as warfarin, apixaban (Eliquis), rivaroxaban (Xarelto), or clopidogrel (Plavix). Without first talking to the doctor who prescribed them. Stopping these medications without medical guidance can be dangerous. Your Mohs surgeon is experienced at operating on patients who take blood thinners and can manage any extra bleeding.

Question 10

Can I eat before Mohs surgery?

Accepted Answer

Yes, please eat a normal meal before your appointment. Mohs surgery uses local anesthesia, not general anesthesia, so fasting is not required. Having food in your stomach helps you stay comfortable and reduces the chance of feeling lightheaded during the procedure. You may also bring a snack to eat during the waiting periods between stages.

Question 11

Do I need someone to drive me home?

Accepted Answer

Having a driver is strongly recommended, especially if the surgery is on your scalp, around your eyes, or on your foot or lower leg. Local anesthesia is used, so you are technically able to drive. But the surgery can take several hours, and you may feel tired or have bulky bandaging that limits your vision or movement. Plan to have a friend or family member available.

Question 12

Should I stop vitamins and supplements before surgery?

Accepted Answer

Yes. Certain vitamins and herbal supplements can increase bleeding. Stop taking vitamin E, fish oil (omega-3), ginkgo biloba, garlic supplements, and ginseng at least 7 days before your surgery. Aspirin used for heart health should not be stopped without your cardiologist's approval. Always bring a complete list of your supplements to discuss at your pre-operative visit.

Question 13

What medications should I mention to my surgeon?

Accepted Answer

Tell your surgeon about all medications you take, including prescription drugs, over-the-counter medicines, vitamins, and herbal supplements. The most important ones to mention are blood thinners, aspirin, anti-inflammatory drugs (ibuprofen, naproxen), immunosuppressants, and steroids. Your surgeon needs this information to plan your care safely.

Question 14

Will Mohs surgery hurt?

Accepted Answer

The area is numbed with a local anesthetic injection before anything else is done. The injection itself feels like a brief sting or pinch, similar to a dental numbing shot. Once the area is numb, you should not feel pain. Only occasional pressure or movement. If you feel discomfort at any point during surgery, tell your surgeon immediately and more anesthetic can be given.

Question 15

How long does Mohs surgery take?

Accepted Answer

Plan to spend most of the day at the office. Typically 3 to 5 hours, though some cases take longer. Each stage of tissue removal takes about 15 to 20 minutes, but processing the tissue under the microscope takes approximately 45 to 90 minutes. Most of your time will be spent waiting comfortably between stages. Bring a book, tablet, or something to keep you occupied.

Question 16

How many stages will I need?

Accepted Answer

Most patients need 1 to 3 stages. About 50% of cases are cleared in a single stage, and over 80% are cleared within two stages. However, it is impossible to predict exactly how many stages you will need in advance. That is part of what makes Mohs unique. Each stage is determined by what the microscope shows, not by a set plan.

Question 17

Am I awake during the surgery?

Accepted Answer

Yes. Mohs surgery is performed under local anesthesia, meaning only the area being operated on is numbed. You are fully awake and aware throughout the procedure. General anesthesia (being put to sleep) is not used in standard Mohs surgery. Most patients watch TV, read, or chat with the staff between stages.

Question 18

What happens between stages?

Accepted Answer

After each layer of tissue is removed, the surgical site is covered with a temporary bandage and you wait while the tissue is processed. In the Mohs lab, a technician prepares thin sections of the tissue, and the surgeon examines them under a microscope. If cancer cells remain, they are mapped precisely so the surgeon knows exactly where to take the next layer. If the margins are clear, the surgery is complete.

Question 19

How will the wound be closed after the cancer is removed?

Accepted Answer

Closure depends on the size and location of the final defect. Options include: direct closure with sutures (stitches pulled together), a skin flap (nearby skin is moved to cover the area), a skin graft (skin taken from another body area), or allowing the wound to heal on its own (called granulation or second-intention healing). Your surgeon will choose the best option for your situation after confirming clear margins.

Question 20

When can I return to work after Mohs surgery?

Accepted Answer

Most patients can return to office or desk work within 1 to 2 days. If your job involves physical labor, heavy lifting, or bending over repeatedly, you may need to wait 1 to 2 weeks. Your surgeon will give you specific guidance based on the location and size of your wound. When in doubt, ask before resuming any work activity.

Question 21

When can I resume exercise after surgery?

Accepted Answer

Light walking is generally fine after surgery, but strenuous activity should be avoided for at least 7 to 14 days. Exercise increases your heart rate and blood pressure, which can cause bleeding, wound opening, and swelling. Activities like running, cycling, swimming, and weightlifting should be cleared with your surgeon before restarting. Swimming in pools or the ocean should wait until the wound is fully healed.

Question 22

How do I care for my wound at home?

Accepted Answer

Keep the wound moist at all times using a thin layer of plain petroleum jelly (Vaseline). Cover it with a non-stick gauze pad and secure it with medical tape. Change the dressing once daily after gently cleaning the area with mild soap and water. Keeping the wound moist helps it heal faster and with less scarring. Your surgeon will provide written instructions tailored to your specific wound type.

Question 23

Will I have a scar after Mohs surgery?

Accepted Answer

Yes, some degree of scarring is unavoidable after any surgical procedure. However, because Mohs surgery removes only the minimal amount of tissue needed, the resulting scars are generally smaller than those from standard excision. Scars typically go through active remodeling for 6 to 12 months after surgery, gradually fading and flattening over time. For cosmetically sensitive areas, your surgeon may refer you to a plastic surgeon for scar revision if needed.

Question 24

What signs of infection should I watch for?

Accepted Answer

Contact your surgeon promptly if you notice any of the following: increasing pain that is not controlled by over-the-counter pain relievers, spreading redness or red streaks around the wound, a wound that feels hot to the touch, yellow or green discharge (pus), swollen lymph nodes nearby, or a fever above 38°C (100.4°F). Minor redness directly at the wound edge in the first 1 to 2 days is normal, but spreading redness is not.

Question 25

Will the skin cancer come back after Mohs surgery?

Accepted Answer

Recurrence after successful Mohs surgery is rare. Less than 1 to 3% for most cancers. However, no treatment can guarantee zero risk, and patients who have had one skin cancer have an increased chance of developing new skin cancers in the future. Annual full-body skin exams by a dermatologist are strongly recommended for all Mohs patients. Catching any new spots early is the best long-term strategy.

Question 26

Is Mohs surgery covered by insurance?

Accepted Answer

Most health insurance plans, including Medicare, cover Mohs surgery when it is deemed medically necessary for appropriate indications. Coverage and out-of-pocket costs vary by plan, location, and individual policy details. It is always wise to contact your insurer before the procedure to confirm coverage, understand your deductible or co-pay, and ask whether pre-authorization is required.