What Is Mohs Surgery and Do I Need It?

Medically reviewed by: Dr. Laurence Bradley | August 2026

Key Points

• Mohs micrographic surgery is the most precise and effective treatment available for the two most common types of skin cancer, basal cell carcinoma and squamous cell carcinoma.
• During Mohs surgery, Dr. Bradley removes thin layers of cancerous tissue one at a time and examines each layer under a microscope until no cancer cells remain.
• Mohs surgery achieves a cure rate of up to 99 percent for primary basal cell carcinoma, the highest of any skin cancer treatment available.
• The procedure is performed right in the office at Legacy Dermatology in Algonquin, IL under local anesthesia on an outpatient basis.
• Not every skin cancer requires Mohs surgery, but it is strongly recommended for cancers on the face, ears, nose, hands, and other cosmetically sensitive or functionally important areas.

If your dermatologist has mentioned Mohs surgery, your first reaction was probably some version of "wait, I need surgery?" It is a word that understandably gives people pause. But once you understand what Mohs surgery actually is and how it works, most patients find it is far less intimidating than it sounds and genuinely the best possible outcome for treating skin cancer effectively while protecting as much healthy skin as possible.

Here is a complete, plain-English guide to what Mohs surgery is, how it works, who needs it, and what to expect when you have it done at Legacy Dermatology in Algonquin, IL.

What Is Mohs Micrographic Surgery?

Mohs micrographic surgery is a specialized surgical technique developed specifically for treating skin cancer. It was developed by Dr. Frederic Mohs in the 1930s and has since become the gold standard treatment for basal cell carcinoma and squamous cell carcinoma, the two most common forms of skin cancer.

What makes Mohs surgery different from other skin cancer treatments is its real-time, layer-by-layer approach. Rather than removing a large section of tissue all at once and sending it off to a lab, Mohs surgery allows the surgeon to immediately examine each layer of tissue under a microscope right there in the office. This process continues until the tissue is completely clear of cancer cells, and not a moment before.

The result is the most precise and tissue-sparing skin cancer treatment available, with cure rates of up to 99 percent for primary basal cell carcinoma. No other skin cancer treatment comes close to that number.

How Does Mohs Surgery Work Step by Step?

Understanding the process makes the whole thing feel much less daunting. Here is exactly what happens during a Mohs surgery procedure at Legacy Dermatology.

Step 1: Numbing the Area

The procedure begins with a local anesthetic injected around the tumor site to numb the area completely. You remain awake and comfortable throughout the entire procedure. Most patients say the injection itself is the most uncomfortable part, and even that is brief.

Step 2: Removing the First Layer

Once the area is numb, Dr. Bradley carefully removes the visible tumor along with a very thin margin of surrounding tissue. A temporary bandage is placed over the wound while the tissue is processed.

Step 3: Mapping and Processing the Tissue

This is what sets Mohs surgery apart from every other approach. The removed tissue is carefully mapped, color-coded, and divided into sections so that Dr. Bradley can precisely track exactly where each piece came from on your skin. The tissue is then processed and examined under a microscope right in the office lab.

Step 4: Microscopic Examination

Dr. Bradley examines 100 percent of the tissue margin under the microscope, checking carefully for any remaining cancer cells. This is critical because traditional pathology only examines a small sample of the margins, which means cancer cells can be missed. Mohs surgery misses nothing.

Step 5: Repeat if Necessary

If cancer cells are found at any margin, Dr. Bradley removes another precise, thin layer from exactly that location only, leaving all the surrounding clear tissue completely untouched. The process repeats until the tissue comes back completely clear.

Step 6: Wound Closure

Once all cancer cells have been removed, Dr. Bradley closes the wound. Depending on the size and depth of the removed tissue, closure may involve simple sutures, a skin flap using nearby tissue, or a skin graft. The goal throughout is always to achieve the cleanest possible result while minimizing scarring. 

What Types of Skin Cancer Does Mohs Surgery Treat?

Mohs micrographic surgery is primarily used to treat the following types of skin cancer.

Basal Cell Carcinoma

Basal cell carcinoma is the most common form of skin cancer. It develops in the basal cells at the base of the outer layer of skin and most often appears on sun-exposed areas like the face, nose, ears, and neck. While it grows slowly and rarely spreads to other parts of the body, it can cause significant local tissue damage if left untreated. Mohs surgery is the most effective treatment option available for basal cell carcinoma, particularly when it appears on the face or other sensitive areas.

Squamous Cell Carcinoma

Squamous cell carcinoma develops in the squamous cells that make up the outer layers of the skin. It carries a slightly higher risk of spreading than basal cell carcinoma, which makes early and thorough treatment especially important. Mohs surgery is highly effective for squamous cell carcinoma and is particularly recommended when the cancer appears in a high-risk location or has aggressive features.

Both of these cancers are detected through a skin biopsy, which is typically the step that precedes a Mohs surgery referral. If you have had a biopsy come back positive for either of these cancers, Mohs surgery is very likely to be part of the conversation about your next steps. 

Who Needs Mohs Surgery?

Not every skin cancer automatically requires Mohs surgery. The decision depends on several factors including the type, size, location, and characteristics of the cancer. Mohs surgery is most strongly recommended when:

The Cancer Is on the Face or Another Cosmetically Sensitive Area

The face, nose, ears, eyelids, and lips are areas where removing too much tissue can have significant cosmetic and functional consequences. Because Mohs surgery removes only cancerous tissue layer by layer rather than cutting out a wide margin all at once, it preserves the maximum amount of healthy surrounding tissue. This makes it the preferred approach for cancers in visible or functionally important locations.

The Cancer Has Poorly Defined Borders

Some skin cancers have edges that are difficult to see clearly with the naked eye. They may appear smaller on the surface than they actually are beneath the skin. Mohs surgery accounts for this by mapping and examining the full margin of every layer removed, ensuring nothing is missed even when the cancer's borders are irregular.

The Cancer Is Large or Recurrent

Larger tumors and cancers that have come back after previous treatment carry a higher risk of incomplete removal with standard excision. Mohs surgery's microscopic approach significantly reduces that risk and offers the highest cure rates even for difficult, recurrent cases.

The Cancer Is in a High-Risk Location

Certain areas of the body carry a higher risk for skin cancer recurrence, including the scalp, ears, and areas around the nose. Mohs surgery is the treatment of choice for high-risk locations where thorough removal is essential.

If you have been diagnosed with skin cancer and are not sure whether Mohs surgery is the right next step for your situation, Dr. Bradley can walk you through the options based on your specific diagnosis, location, and goals. You can also explore the full range of skin cancer treatment options and dermatology services available at Legacy Dermatology. 

What Is Recovery Like After Mohs Surgery?

Recovery from Mohs surgery is generally very manageable, though it does vary depending on the size of the area treated and how the wound was closed.

In the days immediately following the procedure, you can expect some soreness, swelling, and bruising around the surgical site. A bandage will need to be kept over the area for several days while initial healing takes place. Dr. Bradley will provide you with detailed aftercare instructions and schedule follow-up visits to monitor healing.

Most patients are able to return to normal daily activities fairly quickly, though strenuous activity should be avoided for a period of time depending on the location and size of the wound. Dr. Bradley will give you a clear picture of what to expect for your specific situation at your appointment.

Long-term, the goal of the tissue-sparing approach used in Mohs surgery is to minimize scarring while ensuring complete cancer removal. For cancers on the face and other visible areas, this balance between thoroughness and cosmetic outcome is one of the most important reasons Mohs surgery is so widely preferred over other treatment approaches.

Why Choose Dr. Bradley at Legacy Dermatology for Mohs Surgery?

Dr. Laurence Bradley at Legacy Dermatology is a board-certified dermatologist and Mohs surgeon serving patients in Algonquin, IL and the surrounding communities. He brings specialized training in Mohs micrographic surgery along with a deep commitment to achieving the best possible outcomes for each patient.

Dr. Bradley also has a specialty focus on skin of color, which is particularly significant when it comes to skin cancer. People with darker skin tones have a lower overall risk of developing common skin cancers, but when skin cancer does occur in patients of color it is frequently diagnosed at a more advanced stage. Dr. Bradley's expertise means patients of all skin tones receive thorough, expert evaluation and care. Learn more about Dr. Bradley's background and training on the about us page.

Legacy Dermatology is currently welcoming new patients. If you have a suspicious spot you want evaluated or have already received a skin cancer diagnosis, the new patients page is a great place to start. You can also schedule a routine skin check if you are overdue for a full-body skin exam. 

FAQs About Mohs Surgery

Is Mohs surgery painful?

The procedure is performed under local anesthesia, so the treatment area is completely numb throughout. Most patients report that the initial anesthetic injection is the most uncomfortable part, and even that is brief. During the procedure itself, you should feel pressure but not pain. If you feel any discomfort during the procedure, let Dr. Bradley know immediately.

How long does Mohs surgery take?

Because each layer of tissue must be processed and examined before the next step, Mohs surgery typically takes several hours from start to finish. The exact length depends on how many layers need to be removed before the margins are clear. Patients should plan to spend most of the day at the office on the day of their procedure.

Will I have a scar after Mohs surgery?

Some degree of scarring is expected after any surgical procedure. However, because Mohs surgery removes only the cancerous tissue and spares as much healthy surrounding tissue as possible, the resulting scar is typically much smaller than it would be with a wider excision approach. Dr. Bradley will discuss closure options with you and work to achieve the best possible cosmetic outcome.

Can skin cancer come back after Mohs surgery?

Mohs surgery offers the highest cure rates available for basal cell carcinoma and squamous cell carcinoma, with cure rates of up to 99 percent for primary tumors. Recurrence is possible but significantly less likely than with other treatment approaches. Ongoing skin checks after treatment are important for monitoring the treated area and catching any new skin cancers early.

What is the difference between Mohs surgery and a regular excision?

A standard excision removes the tumor along with a predetermined margin of surrounding tissue, which is then sent to an external lab for analysis. Results are typically not available for several days. Mohs surgery processes the tissue immediately in the office and examines 100 percent of the margins in real time, allowing for same-day confirmation that all cancer has been removed. This real-time approach is what gives Mohs surgery its superior cure rates and tissue-sparing results.

Does skin cancer always require Mohs surgery?

No. Smaller, low-risk skin cancers in non-sensitive locations may be treated effectively with cryotherapy, standard excision, or other approaches. Dr. Bradley will evaluate your specific cancer and recommend the most appropriate treatment based on its type, size, location, and characteristics.

FAQs About Legacy Dermatology

Does Legacy Dermatology perform Mohs surgery in the office?

Yes. Mohs micrographic surgery is performed on an outpatient basis right in the Legacy Dermatology office in Algonquin, IL. Local anesthesia is used so patients remain comfortable throughout the procedure.

Is Legacy Dermatology accepting new patients for skin cancer treatment?

Yes. Legacy Dermatology is currently welcoming new patients. Visit the new patients page to get started before your first visit.

What other skin cancer treatments does Legacy Dermatology offer?

In addition to Mohs surgery, Legacy Dermatology offers skin biopsies, cryotherapy, excisions, and routine skin checks. Browse the complete dermatology services page for the full menu.

Where is Legacy Dermatology located?

Legacy Dermatology is at 2230 Huntington Drive N, Unit C-1, Algonquin, IL 60102.

How do I schedule an appointment?

Call (847) 603-4146 or book online. The office is open Monday through Friday, 8:00 AM to 5:00 PM.

A Skin Cancer Diagnosis Is the Beginning, Not the End

Finding out you have skin cancer is scary. But Mohs surgery exists precisely to give patients the most thorough, precise, and tissue-sparing path through it. With cure rates of up to 99 percent, an in-office procedure under local anesthesia, and a board-certified Mohs surgeon right here in Algonquin, you are in very capable hands.

Call (847) 603-4146 or schedule your appointment online today. Dr. Bradley and the team at Legacy Dermatology are here to help you every step of the way.

Disclaimer: The information provided on this blog is for general informational purposes only and is not intended as, and should not be considered, medical advice. All information, content, and material available on this blog are for general informational purposes only. Readers are advised to consult with a qualified healthcare professional for medical advice, diagnosis, or treatment. The author and the blog disclaim any liability for the decisions you make based on the information provided. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.