Question 1

What is Mohs surgery?

Accepted Answer

Named after Mohs (pronounced “moes”) surgery, also known as Mohs micrographic surgery, is a surgical technique used to treat skin cancer. Dr. Frederic Mohs, the surgeon who invented the technique back in the 1930s, the surgery is used to treat many skin cancers, including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), as well as some melanomas, the least common but most deadly type of skin cancer.

“Mohs surgery is also used when tumors come back after traditional excision surgery and when tumors are particularly aggressive or large,” says Dr. Cameron Chesnut, a dermatologic surgeon in Spokane, Washington.

With the more traditional excision approach to skin cancer removal, the surgeon cuts up to a 1 cm margin of extra tissue as “insurance,” to ensure removal of all the cancerous cells, and the patient has to wait up to a week to get pathology results confirming that the cancer is gone.

In contrast, Mohs is performed in precise stages while the patient waits: the surgeon removes a layer of tissue, examines it under a microscope, and then—if any cancer cells remain—removes another layer of tissue in exactly the mapped out area. This process is repeated until the margins are clean, meaning that no cancer cells remain. “It leaves you with the smallest scar possible when compared to other treatments,” says Dr. Nirmal Nathan, a Miami-based plastic surgeon.

The procedure can only be done by a dermatologic surgeon specially trained in the Mohs method. (Many surgeons who claim to be doing Mohs actually utilize a more traditional excisional method.)

Depending on the size, location, depth, and type of tumor they have, some people will need reconstructive surgery after Mohs. That reconstructive procedure can be done by the Mohs surgeon on the same day, or by a plastic surgeon. According to Dr. Nathan, Mohs “allows you to have more advanced reconstructive techniques that involve moving nearby tissue, because the site is confirmed to be cancer-free on the same day.”

Question 2

What are the pros and cons of Mohs surgery?

Accepted Answer

Pros

Mohs can be completed in a single procedure, with same-day testing that gives people immediate peace of mind.
The procedure has a cure rate of up to 99% for skin cancers that haven’t been treated before.
It also has a higher cure rate for high-risk and recurrent BCC and SCC than any other type of skin cancer treatment.
It’s precise enough that it takes less healthy tissue and leaves a much more inconspicuous scar than other treatment options.
The surgery isn’t painful (aside from some brief discomfort from the injection of local anesthesia).

Cons

It’s a slow process—it can take a few hours or an entire day to get clean margins.
Depending on how large the area is and how much skin was removed, recovery time can be significant. You’ll have a line of stitches for 10–14 days and then a red, swollen mark for another two weeks.
Like any surgical procedure, there are risks, including infection, scarring, and temporary or permanent numbness at the surgical site.

Question 3

How much does Mohs surgery cost?

Accepted Answer

How much you’ll pay will depend on your doctor’s level of experience, their office location, the complexity of your case, and how much your insurance will cover. Mohs surgery is typically covered by health insurance plans and Medicare, which may cover reconstruction as well. Call your healthcare provider to confirm your coverage.

The procedure is more expensive than traditional excisional surgery, but it’s the most financially favorable way to treat certain skin cancers, says Dr. Chesnut. “The outcomes are so much better and the recurrence rates so much lower that the cost ends up being lower in the long run.”

See our complete guide to Mohs surgery costs

Question 4

Mohs surgery before and after pictures

Accepted Answer

The Mohs surgery photos in our gallery have been shared by the provider who performed the procedure, with the patient's consent.

Question 5

Who makes a good candidate for Mohs surgery?

Accepted Answer

According to the Skin Cancer Foundation, you’re a good candidate for Mohs surgery if you have high-risk nonmelanoma skin cancer on the nose, eyelids, lips, ears, hands, feet, or genitals, which is where 80% of nonmelanoma skin cancers occur. “Other areas of the face, scalp, neck, and shins are considered ‘intermediate-risk’ but Mohs surgery is appropriate and preferred in those locations as well,” according to Dr. Chesnut.

Mohs is increasingly recommended for people with stage I melanoma and melanoma in situ (stage 0). The Skin Cancer Foundation says, “New advances in this technique make it easier for the surgeon to spot melanoma cells in the margins.” More advanced cases of melanoma may still need a different path of treatment, which could include a combination of surgery, chemotherapy, and radiation. However, “Mohs for melanoma is one of the most cutting-edge utilizations of this technique, with a great deal of research happening, and many of us who are advancing this application use special staining techniques to highlight the melanoma cells, making this the emerging standard of care,” says Dr. Chesnut.

Dermatologists also recommend Mohs surgery for people with large cancers in low-risk areas, cancers that have difficult-to-see borders, and recurrences of skin cancer.

For superficial, low-risk carcinomas, your doctor may recommend other forms of treatment including traditional excision, cryosurgery (freezing), curettage (scooping out the cells), or photodynamic therapy.

Question 6

How do I prepare for Mohs surgery?

Accepted Answer

At your consultation, tell your doctor about any prescription medications of supplements you’re currently taking, in case there are any contraindications.

You’ll also need to avoid alcohol for three days beforehand; it can thin your blood and exacerbate bleeding.

On the day of your procedure, don’t wear makeup or even moisturizer. The surgery is minimally invasive, so you’ll be able to eat beforehand and bring snacks to keep up your energy while you wait for results. Bring something to read or keep you busy while you wait for your results between stages.

It’s also smart to arrange to have someone there to take you home, in case a bulky bandage impairs your vision.

Question 7

What happens during Mohs surgery?

Accepted Answer

Mohs is an outpatient procedure done under local anesthesia, so you’ll be awake. Your surgeon will outline your tumor with a special pen and inject the area with local anesthetic to numb the area. Mohs surgery itself isn’t painful, but some patients feel a burning sensation during the anesthesia injection.

Your doctor will remove a thin layer of cancerous tissue, which is then mapped and frozen to make it easier to slice and analyze. The wound will be bandaged, and you’ll go back to the waiting room while the tissue is processed by specially trained Mohs technicians and then analyzed by your doctor, the same surgeon who removed the tissue, to see if any cancer cells remain. The preparation and tumor removal generally only takes 5–15 minutes. Then, it takes more time to process and analyze the skin, so you might be waiting for an hour or more. You’ll be able to read, listen to music, snack, or go to the bathroom.

If the margins (edges) look clear of cancer cells, the removal process is complete. If not, your surgeon will precisely cut out more tissue based on the mapped areas of positive margins, analyze it, and repeat the process until all cancerous cells have been removed.

After the last round, your doctor may allow the surgical area to heal without sutures—if the area is small, shallow, and in a favorable location.

If the wound is large enough that you’ll need reconstructive surgery, that procedure is usually done immediately afterwards while you are still numb. It can range from very simple side to side (primary) closures to more complex reconstructive techniques, such as a skin graft or skin flap, using your own tissue from another area. In most cases, the Mohs surgeon will do the reconstruction themselves. “Any fellowship-trained Mohs surgeon is going to be the most adept at reconstructing the defects that come after cancer removal in the most cosmetic and functionally sensitive locations. They likely perform thousands of these procedures yearly, so a referral isn’t usually needed,” says Dr. Chesnut. However, Dr. Nathan points out that “you can request a plastic surgeon for sensitive locations such as the nose, eyelids, lips and ears.”

Question 8

How long does Mohs surgery take?

Accepted Answer

Mohs surgery can take anywhere from less than two hours to an entire day, depending on how many rounds of surgery need to be done. Dr. F. Victor Rueckl, a dermatologic surgeon in Las Vegas, says that “it takes about 45 minutes per level [of skin], so most smaller cases are about 90 minutes and larger cases can be three hours.” He notes that in some cases where the cancer was exceptionally large, the patient has even had to return the following day for additional rounds of surgery—though these kinds of situations are rare.

Question 9

What should you expect during Mohs surgery recovery?

Accepted Answer

Most patients experience swelling, bruising, tenderness, and soreness after surgery, especially in the first two to three days. Plan to take a few days off work to heal and recover. You should be able to shower within 24 to 48 hours after your procedure, following your surgeon’s instructions.

The swelling and bruising will be most obvious during the first week after surgery, especially if your procedure was near the eyes or lips. Dr. Ronald Shelton, a New York City-based dermatologic surgeon, also notes that “ears may be more painful than other sites.” If you had surgery on your forehead or nose, your eyelids may swell unexpectedly and impressively, while surgery on your chin or jawline may cause swelling in your neck.

To help reduce swelling and pain, avoid strenuous activity or exercise for the first two to four days, apply an ice pack for 20 minutes each hour, and sleep with your head elevated (if the cancer was removed from your head or face).

The area will be bandaged until your sutures are removed, or until the absorbable sutures have dissolved, typically within one to two weeks.

Dr. Robb recommends that his patients “clean the area daily and keep it covered in ointment to ensure it stays moist, which promotes healing.” Dr. Chestnut agrees an ointment is important. “Petroleum jelly like Vaseline is your healing wound’s best friend. Antibiotics usually aren’t necessary and can actually make the situation worse by causing an inflammatory reaction and delaying the healing. Unless your surgeon wants you on a topical antibiotic ointment, stick with petroleum jelly.”

The 2016 study entitled Update on Postsurgical Scar Management recommends you apply Vaseline (or any petroleum jelly ointment) with a clean Q-tip three times daily for one to three weeks, depending on how you’re healing.

As for when you can wear makeup, “it completely depends on what exactly was done, how big your repair was, and how far along you are in the healing process,” says Dr. Amy Paul, a dermatologic surgeon in Grand Junction, Colorado. “We definitely want patients to wait until their sutures are removed, and the skin is very well closed before adding anything to the surface other than soap, water, and some ointment such as Vaseline or Aquaphor.”

Your scar will look red for about a month and should fade over the next 9 to 12 months. Vaseline can help it look less red, but if your wound is large, you may want to consider other scar treatments like Biocorneum or a laser treatment. Dr. Robb stresses the importance of sun protection during the first year, to reduce the scar’s appearance. For most people, the final scar shouldn’t be very noticeable.

Question 10

How should you bandage your nose or ears after Mohs surgery?

Accepted Answer

How should you bandage your nose or ears after Mohs surgery?

Most dermatologists recommend using a Telfa pad (a surgical dressing) or another type of bandage that’s thick enough to absorb fluid and protect the site, secured with surgical tape that’s easy to remove. Bandaging the nose and ears can be tricky, but your doctor or their nurse should show you how to do it correctly before you head home from your procedure. They may also send you home with extra bandages.

Whatever type of bandage you use, make sure the soft white square completely covers the woundIf your bandage gets wet, remove it and use a fresh one.

Question 11

Are Mohs surgery results permanent?

Accepted Answer

Skin cancer removed by Mohs surgery is permanently gone in most cases. A study published in JAMA Dermatology shows that out of 608 skin cancer tumors, only six removed via Mohs surgery came back, compared to 13 that recurred after excision surgery.

“Mohs gives you the highest cure rate of any modality,” says Dr. Chesnut. “This means you can be the most confident that your tumor is gone [above a 98% certainty for most tumors].”

Question 12

What are the alternatives to Mohs surgery?

Accepted Answer

There really aren’t comparable procedures. “Mohs surgery remains the gold standard for treatment of any well-defined skin cancer on anatomically sensitive areas such as the nose, eyelids, lips, or ears,” says Dr. Stephen Prendiville, a Fort Myers, Florida, facial plastic surgeon, in a RealSelf Q&A.

However, if the cancer is superficial (located in the top layers of skin and considered low-risk) or on a less noticeable area of the body, or the consequence of a lower cure rate and risk for recurrence is viewed as less significant, your doctor may suggest one of these options.

Topical treatments: Superficial nonmelanoma skin cancers are sometimes treated with topical creams or ointments. The drugs most commonly used are imiquimod (Aldaza, Zyclara) and 5-fluorouracil (5-FU, Efudex, Actikerall).

Excision: This procedure may be necessary for certain large tumors or patients with anxiety, who can’t tolerate being awake during surgery. It can be performed in an operating room with a pathologist available, but the pathologist read is only preliminary, with the final result available a week after surgery. The cancerous tumor and some of the surrounding healthy skin is removed with a surgical knife. The wound is closed with stitches. The five-year cure rate is 98% for basal cell carcinomas and 92% for squamous cell carcinomas, according to research published in the Journal of Cutaneous and Aesthetic Surgery.

Cryosurgery: This procedure is typically used for some small basal cell carcinomas. It uses liquid nitrogen to freeze off the cancer. The cure rate is high, but it’s not recommended for high-risk basal cell carcinomas or any type of squamous cell carcinoma, which could potentially metastasize. It leaves a hypopigmented scar.

Curettage and cautery: This can be a good option for superficial, low-risk, nonmelanoma skin cancers. The cancerous tumor is scraped off with a long, thin instrument that has a sharp, looped edge on one end. The area is then zapped with an electric needle, to kill any remaining cancer cells. The procedure has an overall five-year cure rate for basal cell carcinoma of as high as 96% with the most experienced doctors, though the cure rate in most other situations and for high-risk squamous cell carcinomas is lower.

Radiation: If you aren’t able to have surgery or your cancerous growth is on a tricky spot (like the eyelids, nose, or ears), your doctor may recommend radiation treatment. The cure rate is up to 91% for basal cell carcinoma and 90% for squamous cell carcinoma. However, it’s been shown to increase the risk of subsequent basal cell carcinomas and squamous cell carcinomas, so it’s not usually performed on younger patients. “Also keep in mind that radiation will make any future reconstructive surgery more difficult if you have a recurrence at that location,” says Dr. Nathan. “It is also important to note that radiation is not a ‘scarless’ option,” cautions Dr. Chesnut.

Question 13

Sources & studies

Accepted Answer

Papac N. and Collins L., The Female Pioneers in Mohs Micrographic Surgery (2019)

Kauvar A., The Skin Cancer Foundation: Mohs the Gold Standard (2020)

Mary-Chren M., Torres J., and Boscardin W.J., Recurrence after Treatment of Nonmelanoma Skin Cancer (2011)

Commander S.J., Chamata E., Lee E., Update on Postsurgical Scar Management (2016)

Samarasinghe V. and Madan V., Nonmelanoma Skin Cancer (2012)

MOHS SURGERY

Cameron Chesnut, MD, FAAD, FACMS

Colleen Williams

Cameron Chesnut, MD, FAAD, FACMS

Colleen Williams

WE SEND PRETTY
EMAILS

Cameron Chesnut, MD, FAAD, FACMS

Colleen Williams

Cameron Chesnut, MD, FAAD, FACMS

Colleen Williams

MOHS SURGERY REVIEWS

Very Thorough and Skilled Doctor.

MOHS Surgery Upper Lip

Mohs Surgery - Cancer Gone, Nose Preserved!

MOHS SURGERY QUESTIONS

Cryofreezing or MOHS for biopsy spot?

Mohs procedure for basal cell cancer on my scalp - which procedure would be best?

Options for eyelid reconstruction after MOHS surgery? (Photos)

WE SEND PRETTY EMAILS

WE SEND PRETTY
EMAILS