FAQ
Mohs Surgery for Skin Cancer
At Northstar Dermatology, we believe that understanding your treatment helps you feel confident and at ease. Below are answers to the most common questions about Mohs micrographic surgery, the most precise and effective technique for treating many types of skin cancer.
What is Mohs surgery?
What skin conditions are best treated with Mohs surgery?
Mohs surgery is most often recommended for:
- Basal cell carcinoma
- Squamous cell carcinoma
- Certain rare or aggressive skin cancers
- Skin cancers located in cosmetically or functionally sensitive areas (face, ears, eyelids, nose, lips, hands, hairline, feet, or genitals.)
- Recurrent skin cancers that have returned after previous treatment or cases where the initial excision was incomplete.
Do Mohs Surgeons require special qualifications?
Yes, physicians performing Mohs surgery must have specialized training and expertise in dermatology, dermatologic surgery, dermatopathology, and Mohs surgery itself.
Fellowship-trained Mohs surgeons undergo an additional 1-2 years of extensive, hands-on training under highly qualified doctors. By choosing a fellowship-trained Mohs surgeon, you can be confident in receiving the highest standard of care, exceptional expertise, and optimal outcomes. This advanced training makes them experts in Micrographic Surgery and Dermatologic Oncology (Mohs surgery).
Mohs surgery vs. excision: What’s the difference?
Both regular excision and Mohs surgery effectively treat skin cancer, but they differ in how the tissue is examined.
With regular excision, the doctor removes the visible cancer along with a margin of normal-looking skin. The tissue is sent to an outside lab, and confirmation that the cancer is fully removed is received days later. Because only small portions of the edges are examined, there is a small chance that cancer cells at the margins may be missed. This approach works well for low-risk skin cancers in less sensitive areas.
With Mohs surgery, the doctor removes the cancer in thin layers and examines 100% of the tissue edges on the same day, while you wait. If cancer is found, only the affected area is treated further. This allows for the highest cure rates while preserving as much healthy skin as possible.
Complications?
Mohs surgery has an excellent safety record, but like any procedure, there are some potential risks to be aware of. These include:
- Bleeding: Usually minor and stops on its own
- Infection: Rare
- Impaired wound healing: Occasionally the wound may take longer to heal
- Temporary swelling or bruising: Typically resolves within a few days
Your doctor will review these risks with you and provide instructions to help minimize them.
Is Mohs Surgery Painful?
Most patients feel minimal discomfort during Mohs surgery thanks to local anesthesia. Any postoperative pain is usually mild, occurring mostly on the day of surgery and the first day afterward, and typically improves quickly. By one week, only a small number of patients report any pain.
Pain management: The American Academy of Dermatology recommends acetaminophen or NSAIDs (like ibuprofen), which are usually sufficient to control discomfort.
How long does Mohs micrographic surgery take?
Most Mohs procedures are completed within a few hours, but the exact time can vary depending on the size, location, and complexity of the tumor. Because each layer must be processed and analyzed on site, patients should plan to stay at the clinic for the duration of the day, just in case multiple stages are needed.
What happens after Mohs surgery?
- Once all cancer cells have been removed, the surgical site is repaired. Depending on the size and location of the wound, this may involve:
- Allowing it to heal naturally
- Closing it with stitches
- Performing a reconstructive procedure, such as a skin graft or flap, sometimes in collaboration with a plastic or oculoplastic surgeon
You will receive detailed wound care instructions, and most patients can return to normal activities within a few days.
Monitoring is a key part of recovery. Regular skin cancer screenings with your dermatologist are essential to detect any new or recurring skin cancers early.
How does Mohs micrographic surgery work?
The procedure is performed in stages. During each stage:
The surgeon removes a thin layer of tissue from the affected area. That layer is carefully mapped, processed, and examined under a microscope. If cancer cells are found, the surgeon removes another layer exactly where cancer remains.
This process repeats until all cancer cells are gone—ensuring the complete removal of cancer while sparing as much normal skin as possible.