Understanding Mohs Surgery: A Precise Approach to Skin Cancer Treatment

Mohs surgery is a specialized, precise technique that removes skin cancer layer-by-layer under microscopic guidance, offering the highest cure rates and optimal tissue preservation for certain types of skin cancer.

Skin cancer is the most common cancer in the United States, with over 5 million cases treated each year. 

Though mostly curable if caught early, some types of skin cancer like squamous cell carcinoma and basal cell carcinoma can grow deep roots and spread if left untreated. 

In these cases, a precise, layered approach is needed to remove all cancerous tissue while sparing as much healthy skin as possible.

This is where Mohs surgery comes in. While most people are familiar with basic surgical excision for skin cancer removal, Mohs offers a more targeted, controlled technique. 

What is Mohs Surgery, and How Does It Differ From Traditional Skin Cancer Removal Methods?

Mohs surgery, named after Dr. Frederic Mohs who developed it in the 1930s, removes skin cancer in stages under microscopic guidance. Here’s an overview of the specialized Mohs technique:

• Local anesthesia is administered to numb the skin.
• The surgeon removes the visible tumor, plus an extra thin “margin” of clear skin around it.
• This tissue is mapped, color-coded, and microscopically examined immediately by the surgeon.
• If any cancer cells are seen at the edges, the surgeon removes another thin layer of tissue and re-examines it under the microscope.
• This process continues layer-by-layer until the margins are completely clear of cancer.

Traditional excision methods don’t allow for this real-time microscopic analysis. The removed tissue is simply sent to a lab, resulting in a 1-2 week wait for results. If cancer cells are found post-surgery, a second operation is required to clear margins.

Mohs surgery allows complete cancer removal in a single procedure while removing the least amount of healthy tissue. This makes it a highly effective technique.

Which Types of Skin Cancer Are Best Suited for Mohs Surgery, and Why?

The unique precision of Mohs surgery makes it very effective for common skin cancers that take root and spread:

Basal Cell Carcinoma (BCC)

BCC, the most common skin cancer, grows slowly and rarely metastasizes. But some subtypes have root-like extensions that invade deep below the skin. Mohs allows complete tracing and removal of these cancerous roots.

Squamous Cell Carcinoma (SCC)

SCC also grows downward and sideways into surrounding tissues. Mohs helps evaluate the hard-to-see periphery of these tumors to confirm clear margins.

Recurrent Skin Cancers

For skin cancers that return despite initial treatment, Mohs provides the greatest chance for cure. The microscopic approach helps ensure no roots or traces are left behind.

Areas Where Tissue Conservation is Critical

Delicate areas like the face, head, hands, and genitals benefit from Mohs due to better preservation of precious healthy tissue.

What Are the Advantages of Mohs Surgery Over Other Treatment Options?

In addition to its specialized surgical technique, Mohs surgery boasts several advantages that make it one of the “gold standard” treatments for high-risk skin cancers:

• Highest Cure Rates
  For common skin cancers like BCC and SCC, Mohs has 5-year cure rates of up to 99%, surpassing cure rates of excision, cryotherapy, and radiation therapy.
• Tissue Conservation
  By microscopically examining margins and removing the absolute minimum needed layer-by-layer, Mohs preserves as much healthy tissue as possible. This minimizes scarring and disfigurement.
• Minimal Scarring
  When cancer removal leaves only a very small wound, recovery is quicker and scarring is often negligible. This makes Mohs ideal for facial cancers.
• Accuracy
  The instant feedback from microscopic analysis during surgery makes Mohs very accurate in tracing out elusive cancer roots.
• Efficiency
  Rather than requiring multiple surgeries if margins are positive, Mohs removes all cancer in a single procedure.
• Versatility
  Mohs can be used to treat any type of skin cancer anywhere on the body. It’s also very effective for rare cancers like dermatofibrosarcoma protuberans.

Are There Any Risks or Drawbacks Associated With Mohs Surgery?

While generally safe and highly effective, Mohs surgery does carry some potential risks and limitations to consider:

• Bleeding - Oozing from the surgery site may persist for 1-2 days. Applying pressure is usually sufficient, but rarely a blood transfusion or cauterization is required.
• Infection - As with any surgical procedure, infection is possible but uncommon with proper wound care. Signs include worsening redness, swelling, warmth, and pus. Antibiotics can treat minor infections.
• Poor Wound Healing - Occasionally the surgical site won’t heal properly, especially if the wound is large or intricate. This may require follow-up surgery for scar revision or skin grafts.
• Scarring - While most Mohs scars are minimal, wider or deeper tumors may result in disfiguring scars, especially on the face. Proper wound closure technique helps reduce scarring.
• Recurrence - In very rare cases, skin cancer can return post-Mohs. This highlights the importance of close follow-up exams. Early detection allows recurrences to be treated promptly with repeat Mohs.
• Specialized Technique - Mohs requires extensive training. Not all dermatologic surgeons offer it, limiting widespread availability.

What Can a Patient Expect During and After Mohs Surgery?

Want to know what your Mohs surgery day will really be like? Here’s a step-by-step overview:

During Mohs Surgery

• You’ll arrive at the surgical suite and have the area numbed with local anesthesia. This feels like a slight stinging/burning sensation.
• The visible tumor is removed along with a thin margin of clear skin surrounding it. You likely won’t feel anything during the actual removal.
• Pressure is applied to control any bleeding. The wound is temporarily bandaged while the tissue is mapped, color-coded, and microscopically analyzed.
• You’ll wait about 1 hour for the tissue analysis. The surgeon will review the slides and determine if more skin layers need removal.
• If microscopic examination shows remaining cancer cells, the process repeats in thin additional layers until all margins are cancer-free.
• Once clear margins are achieved, the surgeon repairs the wound with stitches or a skin graft.

After Mohs Surgery

• Keep the wound area clean and dry for proper healing. Avoid strenuous exercise for 1-2 weeks.
• Bruising, swelling, and discomfort are common and typically peak at 48 hours, then gradually improve.
• Take over-the-counter pain medication as needed for pain relief.
• Some temporary numbness or itching at the surgery site is normal during the healing process.
• Follow up with your surgeon as directed to check wound healing and remove any stitches.
• Schedule regular skin exams to monitor for recurrence. Report any suspicious lesions or symptoms promptly.

Is Mohs Surgery Covered By Insurance, and How Much Does It Typically Cost?

The good news is that Mohs surgery is usually covered by insurance, including Medicare, when medically necessary to treat an existing skin cancer. Out-of-pocket costs depend on your specific insurance plan and deductible amount. On average though, expect to pay:

• Surgeon’s Fee: $500 - $1,500 per Mohs treatment session.
• Anesthesia Fee: $200 - $300
• Facility Fee: $400 - $1,000

For complex or recurrent cancers requiring additional Mohs stages, costs may run higher. Verify your insurance benefits and get a cost estimate ahead of time so you aren’t surprised by bills. Reconstructive plastic surgery to repair larger defects also adds to the overall cost.

How Do I Find a Qualified Mohs Surgeon, and What Questions Should I Ask Them?

Finding an experienced, reputable Mohs surgeon is key to getting the best results. Start by searching the American College of Mohs Surgery website, which certifies surgeons based on extensive training requirements. Here are other tips:

• Verify board certification in Mohs micrographic surgery.
• Look for a surgery volume of at least 500 Mohs cases per year.
• Ask about the surgeon’s specialty training in Mohs and years of experience.
• See before and after photos of the surgeon’s Mohs patients.

During consultations, come prepared with questions including:

• How many Mohs cases have you performed for my specific type of skin cancer?
• Should Mohs surgery be the first treatment option in my case? If not, why?
• How will you minimize scarring based on the tumor’s location?
• How long will the procedure take, and what is the recovery process like?
• What is the risk of recurrence after Mohs? How will you monitor for this?

Final Thoughts

Mohs micrographic surgery offers an unparalleled level of accuracy, control, and tissue preservation for high-risk skin cancers. While no surgery is risk-free, Mohs provides the highest cure rates and optimal cosmetic results. 

Working with a skilled, experienced Mohs surgeon is key to achieving success. For certain recurrent or aggressive skin cancers, Mohs may be the most effective option and is worth discussing with your dermatologist.