After being diagnosed with skin cancer, you may hear more than one surgical treatment mentioned. Two of the most common are Mohs surgery and standard surgical excision.
Both procedures are designed to remove skin cancer, and both can be highly effective when used appropriately. The biggest difference is how the cancer is removed and how the surgical margins are examined to make sure no cancer cells remain.
Mohs surgery removes and examines tissue in carefully mapped stages during the same appointment. Standard excision removes the visible cancer along with a predetermined margin of surrounding healthy-looking skin, which is then sent to a laboratory for examination.
At Evolve Dermatology, our fellowship-trained Mohs surgeons provide comprehensive skin cancer treatment for patients throughout Plano, Forney, Dallas, and North Texas. The appropriate treatment depends on several factors, including the type, size, location, borders, and risk characteristics of your skin cancer.
Understanding how these two procedures differ can help you better understand why your dermatologist may recommend one approach over the other.
What Is Standard Excision for Skin Cancer?
Standard surgical excision is a commonly used treatment for skin cancer. During the procedure, your dermatologist removes the visible tumor along with a predetermined margin of normal-appearing skin surrounding it. The removed tissue is then sent to a pathology laboratory, where it is examined microscopically to determine whether cancer cells extend to the edges, or deep margins, of the specimen.
If the margins are clear, no additional surgery may be necessary. If cancer cells are found at a margin, additional treatment may be recommended to remove remaining cancer.
Standard excision is frequently used for skin cancers that can be adequately treated using established surgical margins and is an effective option for many basal cell carcinomas, squamous cell carcinomas, melanomas, and other skin cancers.
What Is Mohs Surgery for Skin Cancer
Mohs surgery takes a different approach to removing and examining skin cancer.
Instead of removing the tumor with a predetermined margin of surrounding tissue all at once, your Mohs surgeon removes the visible cancer along with a thin layer of surrounding tissue.
That tissue is carefully mapped, processed, and examined under a microscope during your appointment.
If cancer cells are detected at any edge or deep margin of the removed tissue, your surgeon knows exactly where they remain. Another thin layer can then be removed specifically from that area rather than removing additional tissue around the entire surgical site.
This process continues until the examined margins are free of cancer cells.
Because Mohs surgery allows the surgeon to track the tumor microscopically while preserving uninvolved tissue, it combines comprehensive margin evaluation with a tissue-sparing surgical approach. Explore our What Is Mohs Cancer Surgery? guide for a step-by-step explanation of what to expect before and during treatment.
What Is the Main Difference Between Mohs Surgery and Standard Excision?
Both procedures remove the visible skin cancer and evaluate the surrounding margins. The primary difference is how those margins are examined and how the results guide additional tissue removal. With standard excision, the tumor and a predetermined margin are removed in one procedure and the specimen is sent to a pathology laboratory for evaluation. If the pathology report later shows cancer cells at the margin, additional treatment may be necessary.
With Mohs surgery, tissue is examined during the procedure itself. If cancer remains, the surgeon removes another layer precisely from the area where those cells were identified. The process continues until no additional cancer cells are detected at the examined margins.
That difference can be particularly important when a skin cancer has irregular or difficult-to-see borders or is located somewhere where a tissue sparing technique is particularly critical.
Why Does Mohs Surgery Preserve More Healthy Tissue?
Skin cancers do not always grow in a perfectly predictable shape. What appears on the surface may not reveal the exact extent or direction of cancer cells beneath the skin. Removing a predetermined margin around the entire tumor helps account for this possibility during standard excision.
Mohs surgery approaches the problem differently. Because each stage is mapped and examined microscopically before the next stage is taken, the surgeon can remove additional tissue only where cancer cells remain.
This tissue-sparing approach is especially valuable in areas such as the:
- Nose
- Eyelids
- Lips
- Ears
- Scalp
- Hands
- Feet
- Face
- Shins
In these locations, preserving even a relatively small amount of healthy tissue can be important for maintaining appearance, function, or both.
Does Mohs Surgery Have a Higher Cure Rate Than Standard Excision?
Mohs surgery has very high cure rates for appropriately selected skin cancers and is considered the treatment with the highest cure rate for many common skin cancers.
That does not mean every skin cancer needs Mohs surgery.
Standard excision can also provide excellent cure rates when used for appropriately selected tumors. The advantage of Mohs is particularly important when a cancer has characteristics that increase the risk of recurrence or make determining its borders more difficult.
Choosing between Mohs and standard excision is about selecting the treatment appropriate for the particular cancer being treated.
When Is Mohs Surgery Recommended Instead of Standard Excision?
Mohs surgery is commonly considered when a skin cancer:
- Is located on the face, ears, scalp, hands, feet, shins or another area where tissue preservation is particularly important
- Has poorly defined borders
- Is large or aggressive
- Has a higher risk of recurrence
- Has returned after previous treatment
- Is located in an area previously treated with radiation
- Has other characteristics that make complete margin evaluation especially important
Mohs is most commonly used for basal cell carcinoma and squamous cell carcinoma, although it may also be appropriate for certain other skin cancers. Your dermatologist considers the complete clinical picture before determining the most appropriate treatment option.
When Might Standard Excision Be the Better Choice?
Not every skin cancer requires the additional margin control provided by Mohs surgery.
Standard excision may be appropriate for many lower-risk, well-defined skin cancers, particularly when they are located in areas where removing an established margin of surrounding tissue is unlikely to create significant functional or cosmetic concerns.
It is also commonly used in the treatment of melanoma. For early-stage melanoma, surgical excision with margins determined by the characteristics of the melanoma remains a standard treatment approach.
The best treatment is the one that appropriately treats the specific cancer while considering its location, behavior, and the surrounding healthy tissue.
Is Mohs Surgery Only Used on the Face?
No. Mohs surgery can be performed on many areas of the body. However, it is particularly valuable in areas where healthy tissue is limited or where unnecessary tissue removal could affect appearance or function. This is why patients frequently associate Mohs with skin cancers of the nose, eyelids, ears, lips, and other facial areas.
Tumor type, size, recurrence risk, borders, and other characteristics can also make Mohs appropriate even when a skin cancer is not located on the face.
Is Recovery Different After Mohs Surgery and Standard Excision?
Recovery from either procedure depends heavily on the size and location of the cancer and how the surgical site is repaired. After standard excision, the wound may be closed during the procedure, depending on the size and location of the treatment area.
With Mohs surgery, reconstruction is generally planned after the surgeon has confirmed that the examined margins are free of cancer. Depending on the resulting wound, repair may involve stitches, a skin flap, a graft, or allowing the area to heal naturally. Some larger or more complex wounds may require reconstruction by another surgeon.
Swelling, tenderness, bruising, and temporary changes in sensation may occur with either procedure. Your surgeon will provide wound-care and activity instructions based on your specific treatment.
How Will My Dermatologist Decide Between Mohs Surgery and Standard Excision?
The recommendation is based on the characteristics of your particular skin cancer rather than a one-size-fits-all treatment rule.
Your dermatologist may consider:
- The type of skin cancer
- Tumor size
- Tumor location
- How clearly the borders can be identified
- Whether the cancer has aggressive characteristics
- Whether it has been treated previously
- Risk of recurrence
- Your medical history
- The importance of preserving healthy tissue in the treatment area
Treatment for various skin cancers depend on factors including the cancer’s subtype, size, depth, and location, with both wide local excision and Mohs micrographic surgery among the treatment options.
The goal is not to choose the most complex procedure. It is to choose the treatment that provides appropriate cancer control while preserving healthy tissue whenever possible.
FAQs About Mohs Surgery vs. Standard Excision
Is Mohs surgery more serious than standard excision?
Not necessarily. Being referred for Mohs does not automatically mean your skin cancer is more advanced or dangerous. Mohs may be recommended because of the cancer’s location, borders, recurrence risk, or the importance of preserving surrounding healthy tissue.
Are you awake during Mohs surgery?
Yes, most Mohs surgery is performed in an office or surgical setting using local anesthesia, so patients remain awake during the procedure.
Do you get pathology results immediately with Mohs surgery?
The removed tissue is processed and examined during the appointment. This allows the Mohs surgeon to determine whether cancer cells remain at the examined margins before proceeding with another stage or reconstruction.
What happens if standard excision shows positive margins?
If pathology identifies cancer cells at the margins of the removed specimen, it may indicate that cancer remains. Your dermatologist will discuss whether additional surgery or another treatment is needed based on the type of cancer and individual circumstances.
Can basal cell carcinomas and squamous cell carcinomas be treated with either Mohs or standard excision?
Yes. Both may be appropriate treatments for basal cell and squamous cell carcinomas. The choice depends on factors such as subtype, size, depth, location, borders, previous treatment, and recurrence risk. Evolve Dermatology offers both wide local excision and Mohs micrographic surgery as treatment options for BCC and SCC.
Learn Which Skin Cancer Treatment at Evolve Dermatology Is Right for You
If you’ve been diagnosed with skin cancer, hearing that there is more than one surgical option can create another question: Which treatment is right for me? The answer depends on your diagnosis, the characteristics and location of the cancer, and your individual treatment needs.
At Evolve Dermatology, our fellowship-trained Mohs surgeons provide comprehensive skin cancer care for patients throughout Plano, Forney, Dallas, and North Texas. Our team can explain why Mohs surgery, standard excision, or another treatment has been recommended and help you understand what to expect throughout the process.
Contact Evolve Dermatology to schedule an appointment and learn more about your skin cancer treatment options.