Mohs Surgery: How It Works, Cure Rates, Risks, and Recovery
Updated: 6 days ago
Written and medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026 · How we review
Quick Answer: What is Mohs surgery?
Mohs surgery is a precise outpatient procedure that removes high-risk skin cancer one thin layer at a time while checking 100% of the edges under a microscope. It mainly treats basal cell and squamous cell carcinoma, spares healthy skin, and has cure rates of up to 99%. [1]
What the research says
Mohs surgery lowers recurrence compared with standard surgery. A meta-analysis of 17 studies (6,503 tumors) found recurrence in 3.1% of tumors treated with micrographic surgery versus 5.3% with conventional surgery — about half the relative risk (RR 0.48). The benefit was clearest for basal cell carcinoma (RR 0.37). (Lacerda et al., J Eur Acad Dermatol Venereol, 2024) [2]
Serious complications are extremely rare. A prospective study of 20,821 Mohs procedures at 23 U.S. centers recorded adverse events in 0.72% of cases, serious events in 0.02%, and no deaths. Infection was the most common problem. (Alam et al., JAMA Dermatology, 2013) [3]
Most people feel only mild pain afterward. In a multicenter study of 1,550 patients (1,792 tumors), no major complications occurred, minor complications affected 2.6%, and average peak pain was 1.99 on a 0–10 scale. (Merritt et al., J Am Acad Dermatol, 2012) [4]
Key takeaways
Mohs surgery removes skin cancer in thin layers and examines each one under a microscope until no cancer cells remain. [1]
It checks 100% of the deep and side edges, compared with less than 1% in a standard wide excision. [1]
Cure rates reach up to 99% for new basal cell carcinoma and 95%–99% for new squamous cell carcinoma. [1]
You stay awake under local anesthesia, and the whole process usually takes a few hours to a full day. [1]
Scars keep healing for 12 to 18 months, and sun protection with SPF 30 or higher helps them fade. [1]
What is Mohs surgery?
Mohs surgery is a skin cancer operation in which your surgeon removes the tumor in thin layers and checks each layer under a microscope during the same visit. Its full name is Mohs micrographic surgery. [1]
The surgeon starts with the visible part of the tumor plus a small rim of skin around it. The sides and deep edges (margins) of that tissue are then examined under a microscope. [1]
If cancer reaches any edge, the surgeon removes more tissue only from that spot and checks it again. This repeats until all the cancer is gone. [1]
Because only cancerous tissue is removed, healthy skin is spared. That makes Mohs especially useful on the face, scalp, ears, hands, feet, and genital area, where every millimeter of skin matters. [1]
Why is Mohs surgery called "Mohs"?
The original method used a chemical to preserve the tumor before removal. Preparing those tissue slides took several days, the chemicals were controversial, and the process was painful. [1]
About 20 years later, Dr. Mohs and his colleagues switched to frozen fresh tissue while treating an eyelid cancer. This allowed the whole surgery to be finished in one day — the basis of the modern procedure. [1]
How is Mohs surgery different from standard excision?
Mohs surgery differs from standard excision mainly in how much of the tissue edge is checked under the microscope. [1]
Feature | Mohs micrographic surgery | Standard (wide local) excision |
Margin of healthy skin removed | Smaller | Wider, preset margin |
Edges checked under microscope | 100% of deep and side margins | Less than 1% of margins |
Who reviews the tissue | Your surgeon, during the visit | A pathology lab, after surgery |
Results available | Same day, before the wound is closed | Days later |
Main advantage | Complete margin check, maximum skin sparing | Simpler, widely available |
Source: [1]
This complete margin check is why Mohs surgery has the lowest recurrence rate of any skin cancer treatment. [1] A 2024 meta-analysis confirmed roughly half the relative risk of recurrence compared with conventional surgery. [2]
Which skin cancers does Mohs surgery treat?
Mohs surgery mainly treats the two most common skin cancers: basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). [1]
It is also sometimes used for less common skin cancers, including: [1]
Certain melanomas
Microcystic adnexal carcinoma
If you have been diagnosed with squamous cell carcinoma of the skin, ask your dermatologist whether your tumor's size, depth, or location makes Mohs the best option.
Where is Mohs surgery done?
Mohs surgery is done in a doctor's office or an outpatient surgical center, so you go home the same day. [1]
After each layer is removed, you wait in a waiting room or the operating room while your care team prepares slides and your surgeon examines them. If cancer remains at any edge, you are called back for another layer. [1]
Waiting can take a while. Bring a book or a charged device to pass the time. [1]
What happens before Mohs surgery?
Before Mohs surgery, your dermatologist examines the cancer site and the skin around it. [1]
Together, you will review: [1]
Your medical history, medicines, and supplements
Your skin biopsy results
Your diagnosis, treatment options, and the risks and benefits of Mohs surgery
Depending on your overall health and where the cancer is, you may need antibiotics before surgery. [1]
How is Mohs surgery performed?
Mohs surgery is performed in repeated cycles of removing a thin layer of skin and checking it under a microscope. [1]
Step | What happens |
1. Numbing | The skin around the cancer is numbed with an injected local anesthetic. |
2. Debulking | Any visible, raised part of the tumor is removed. |
3. Thin layer removal | A thin layer of tissue is taken, saving as much healthy skin as possible. |
4. Mapping | The tissue is marked (top, bottom, left, right) and a map of the site is drawn. |
5. Lab processing | The tissue is frozen, cut, and stained on-site — usually about one hour. |
6. Microscope check | The surgeon examines the entire bottom and outer edges of the layer. |
7. Repeat if needed | If cancer remains, another thin layer is removed only from that exact spot. |
Source: [1]
The cycle ends when no cancer cells are seen. [1]
Are you awake during Mohs surgery?
Yes, most people are awake during Mohs surgery. [1]
The area is numbed with injections, so you feel pressure and touch but no pain. If another layer is needed, the area may still be numb, or you may receive more injections. [1]
Feeling anxious? That is very common. Music or a guided meditation can help during the procedure, and your provider may offer anti-anxiety medicine beforehand. [1]
How long does Mohs surgery take?
Mohs surgery can take a few hours or a full day. [1]
The time depends on the tumor. Bigger and deeper tumors need more layers, so they take longer to remove completely. [1]
Will you need reconstruction after Mohs surgery?
Whether you need reconstruction after Mohs surgery depends on the size and location of the wound left behind. [1]
Your surgeon may recommend: [1]
Healing on its own (second intention healing)
Stitches (sutures)
A skin flap (nearby skin moved over the wound) or a skin graft (skin taken from another body site)
A combination of these options
Another specialist, such as an oculoplastic surgeon (around the eye) or a facial plastic surgeon — usually for a larger-than-expected tumor
How successful is Mohs surgery?
Mohs surgery has the highest cure rate of all treatments for basal cell and squamous cell skin cancers. [1]
Cancer type | New (primary) cancer | Recurrent cancer |
Basal cell carcinoma | Up to 99% | Up to 94% |
Squamous cell carcinoma | 95%–99% | 90% |
Source: [1]
Cure rates are lower for cancers that have come back after earlier treatment. Regrowth is also more common with large, long-standing tumors. [1]
What are the advantages of Mohs surgery?
The main advantages of Mohs surgery are complete removal of the cancer, high cure rates, and maximum sparing of normal skin. [1]
Other benefits include: [1]
It is done in a single outpatient visit.
Only local anesthesia is used, so recovery is faster than with general anesthesia or sedation.
What are the risks of Mohs surgery?
The risks of Mohs surgery are very low. [1] In a study of more than 20,000 procedures, serious events occurred in just 0.02% of cases. [3]
Possible risks include: [1]
Scarring
A larger wound than expected
Poor wound healing
Excessive bleeding
Infection
Loss of nerve function (movement or feeling), which may be temporary or permanent
Regrowth of the tumor, more common with previously treated or large, long-standing tumors
Discuss your own health conditions and concerns with your surgeon before the procedure. [1]
How painful is recovery from Mohs surgery?
Recovery from Mohs surgery usually involves mild to moderate pain that fades over a few days. [1]
Acetaminophen (Tylenol®) usually controls it well. [1][5] People who have surgery on the scalp, or whose wound is larger than 3 square centimeters, tend to report more pain. [1]
How do you care for your wound after Mohs surgery?
Wound care after Mohs surgery starts with leaving the first dressing alone for 24 to 48 hours, or as your surgeon directs. [1]
After that: [1]
Remove the dressing for wound care twice a day, or as directed.
Clean the wound with 3% hydrogen peroxide or a mild soap.
Cover it with petroleum jelly (Vaseline®).
Apply a non-stick dressing.
Keep using petroleum jelly at least until your stitches come out, usually in one to two weeks. Your surgeon may ask you to continue for another couple of weeks. [1]
Your surgeon will also advise you to: [1]
Avoid strenuous exercise and heavy lifting for at least one week.
Apply ice or cold packs regularly in the first days to reduce swelling and bruising — never directly on the skin.
How long does it take to heal from Mohs surgery?
Scars from Mohs surgery keep healing for 12 to 18 months. [1]
During the first year, the scar slowly matures and fades. Once a dressing is no longer needed, protect the scar with sunscreen of at least SPF 30 and a hat whenever you are in the sun. [1]
If you are unhappy with your scar, ask your surgeon about scar revision options. [1]
When should you call your doctor after Mohs surgery?
Call your surgeon after Mohs surgery if bleeding will not stop, pain is not controlled, or you notice signs of infection. [1]
Problem | What is normal | Call your surgeon if… |
Bleeding | A little oozing in the first few hours; pressure stops it | Bleeding does not stop with pressure |
Pain | Mild to moderate discomfort | Acetaminophen does not help, pain lasts beyond a few days, or it improves and then worsens |
Infection | — | Fever; thick, yellowish discharge or a foul smell; bright red skin around the wound; swollen skin that is hot to the touch |
Source: [1]
An infected wound can slow recovery and affect how well the scar heals. You may need antibiotic cream or tablets. [1]
Conclusion
Mohs surgery offers a rare combination in cancer care: very high cure rates with as little healthy tissue removed as possible. By checking every edge of every layer under the microscope, your surgeon can confirm the cancer is gone before you leave — often in a single day. [1]
If skin cancer is caught early, before it spreads, this precise procedure may cure it in one visit. [1] Recovery is usually comfortable, serious complications are rare, and good wound care plus sun protection gives your scar the best chance to fade. [1][3]
Have a spot that won't heal or a new skin cancer diagnosis? Book a visit with a dermatologist and ask whether Mohs surgery fits your case. To keep learning, read our guides to actinic keratosis, a common precancer, and melanoma warning signs — and explore more evidence-based health guides on Rinnit.com.
FAQ
What is Mohs surgery used for?
Mohs surgery is used mainly to remove basal cell carcinoma and squamous cell carcinoma, the two most common skin cancers. It is also sometimes used for certain melanomas, dermatofibrosarcoma protuberans, sebaceous carcinoma, and extramammary Paget disease.
Is Mohs surgery painful?
Mohs surgery itself is not painful because the area is numbed with a local anesthetic, so you feel only pressure and touch. Afterward, most people have mild to moderate pain for a few days that acetaminophen usually controls.
How long does Mohs surgery take?
Mohs surgery takes anywhere from a few hours to a full day. Larger and deeper tumors need more layers removed, so they take longer.
What is the success rate of Mohs surgery?
Mohs surgery cures up to 99% of new basal cell carcinomas and 95%–99% of new squamous cell carcinomas. Rates are slightly lower for cancers that have come back after earlier treatment.
Is Mohs surgery better than standard excision?
Mohs surgery checks 100% of the tissue edges, while standard wide excision checks less than 1%. This gives Mohs the lowest recurrence rate of any skin cancer treatment and spares more healthy skin.
Will Mohs surgery leave a scar?
Mohs surgery leaves a scar, but it continues to heal and fade for 12 to 18 months. Sunscreen of SPF 30 or higher and protective hats help it heal well, and scar revision is an option if needed.
How long should I use Vaseline after Mohs surgery?
Petroleum jelly (Vaseline) should be used on the wound at least until the stitches are removed, usually one to two weeks after surgery. Your surgeon may advise continuing for another couple of weeks.
When should I call my surgeon after Mohs surgery?
Call your surgeon after Mohs surgery if bleeding does not stop with pressure, pain is not relieved by acetaminophen or gets worse, or you develop fever, yellow discharge, a foul smell, or red, hot, swollen skin around the wound.
Who performs Mohs surgery?
Mohs surgery is performed by a dermatologist with special training in Mohs surgery. The same doctor removes the cancer and checks the tissue under the microscope.
How should I prepare for Mohs surgery?
Plan to be there for most of the day, eat normally and bring a snack and something to do. Keep taking your usual medicines, including blood thinners, unless your doctor tells you otherwise.
Related Reading
Skin Graft: Types, Surgery and Recovery explains skin graft surgery and recovery.
References
Cleveland Clinic. Mohs Surgery: For Skin Cancer, Procedure, Risks, Recovery. Cleveland Clinic. Last updated August 31, 2022. https://my.clevelandclinic.org/health/treatments/13312-mohs-surgery
Lacerda PN, Lange EP, Luna NM, et al. Efficacy of micrographic surgery versus conventional excision in reducing recurrence for basal cell carcinoma and squamous cell carcinoma: A systematic review and meta-analysis. J Eur Acad Dermatol Venereol. 2024;38(6):1058-1069. PMID 38116955. https://doi.org/10.1111/jdv.19743
Alam M, Ibrahim O, Nodzenski M, et al. Adverse events associated with mohs micrographic surgery: multicenter prospective cohort study of 20,821 cases at 23 centers. JAMA Dermatol. 2013;149(12):1378-1385. PMID 24080866. https://doi.org/10.1001/jamadermatol.2013.6255
Merritt BG, Lee NY, Brodland DG, et al. The safety of Mohs surgery: a prospective multicenter cohort study. J Am Acad Dermatol. 2012;67(6):1302-1309. PMID 22892283. https://doi.org/10.1016/j.jaad.2012.05.041
Limthongkul B, Samie F, Humphreys TR. Assessment of postoperative pain after Mohs micrographic surgery. Dermatol Surg. 2013;39(6):857-863. PMID 23464845. https://doi.org/10.1111/dsu.12166
Brodland DG, Amonette R, Hanke CW, et al. The history and evolution of Mohs micrographic surgery. Dermatol Surg. 2000;26(4):303-307. PMID 10759814. https://doi.org/10.1046/j.1524-4725.2000.00504.x
Further reading (external):
American College of Mohs Surgery. About Mohs Surgery. American College of Mohs Surgery. Accessed October 31, 2026. https://www.mohscollege.org/for-patients/about-mohs-surgery
The Skin Cancer Foundation. Mohs Surgery. The Skin Cancer Foundation. Last updated October 2025. https://www.skincancer.org/treatment-resources/mohs-surgery/
Prickett KA, Ramsey ML. Mohs Micrographic Surgery. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing. Last updated July 25, 2023. PMID 28722863. https://www.ncbi.nlm.nih.gov/books/NBK441833/
Disclaimer
This article is for general education only and does not replace professional medical advice, diagnosis, or treatment. Always talk with a qualified dermatologist or surgeon about your own situation.
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