Mohs Surgery Is Effective For Treating These Types Of Skin Cancer

Skin cancer is the most common form of cancer in the United States, with more than 5 million cases diagnosed each year. Among the many treatment options, Mohs surgery stands out as one of the most effective and precise techniques. Developed by Dr. Frederic Mohs in the 1930s, this specialized procedure has evolved into the gold standard for treating certain skin cancers, especially those occurring in cosmetically or functionally important areas.

What is Mohs Surgery?

Mohs surgery is a meticulous, layer-by-layer removal technique designed to excise skin cancer while preserving as much healthy tissue as possible. The process involves:

• Removing a narrow margin around cancerous tissue.
• Examining that margin under a microscope immediately.
• Continuing the process, layer by layer, until no cancer cells remain.

This real-time evaluation ensures complete cancer removal with maximum tissue conservation.

Why it’s Considered the Gold Standard

Mohs surgery is especially valued for its high cure rates, tissue-sparing precision, and immediate margin control. Mohs has the highest success rates of all skin cancer treatments and is ideal for areas like the face, ears, hands, and genitals where function and appearance are critical. Additionally, surgeons can verify complete cancer removal during the procedure.

This blog post will explore which types of skin cancer are best treated with Mohs surgery, and when other options might be more appropriate.

1. Mohs Surgery for Basal Cell Carcinoma (BCC)

Basal cell carcinoma is the most common type of skin cancer, accounting for about 80% of non-melanoma skin cancers. BCC typically grows slowly and rarely spreads to other parts of the body, but it can cause significant local tissue damage if left untreated.

Mohs surgery is often the preferred treatment for BCC when:

• The tumor is located in cosmetically sensitive or high-risk areas, such as the nose, lips, eyelids, ears, and scalp.
• The cancer is recurrent, meaning it has returned after previous treatment.
• The BCC has aggressive histological features, such as infiltrative or morpheaform subtypes.

Success rate

• Up to 99% for primary (first-time) BCCs.
• Approximately 94% for recurrent BCCs.

2. Mohs Surgery for Squamous Cell Carcinoma (SCC)

Squamous cell carcinoma is the second most common type of skin cancer. Unlike BCC, SCC tends to grow more quickly and carries a higher risk of metastasis (spreading), especially in immunocompromised individuals or if left untreated.

Mohs is typically recommended for SCCs that are:

• Located on high-risk areas such as the face, ears, hands, feet, or genitals.
• Recurrent or previously treated.
• Present in immunocompromised patients (e.g., organ transplant recipients).
• Showing high-risk features under the microscope, such as poor differentiation or perineural invasion.

Success rate

• Approximately 97% for primary SCCs.
• Around 90% for recurrent SCCs.

3. Mohs Surgery for Squamous Cell Carcinoma in Situ (Bowen’s Disease)

Also known as Bowen’s disease, this is a very early form of SCC that has not yet invaded deeper layers of the skin. It appears as a scaly, red patch and is confined to the epidermis.

Mohs surgery may be used when:

• The lesion is on cosmetically or functionally sensitive areas such as the face or genital region.
• The carcinoma has not responded to less invasive treatments like topical therapies or cryotherapy.

Success rate

• 98–99%, with low recurrence rates, when treated with Mohs.

4. Mohs Surgery for Lentigo Maligna (Melanoma In Situ)

Lentigo maligna is a slow-growing form of melanoma in situ (early-stage melanoma that hasn’t yet penetrated deeper skin layers), commonly found on sun-damaged facial skin in older adults.

Although not traditional for melanoma, Mohs can be used for lentigo maligna under special circumstances:

• When large and/or located on cosmetically sensitive areas, such as the face, neck, or ears.
• When immunohistochemical stains (like MART-1) are used in the Mohs laboratory to better identify melanoma cells under the microscope during surgery.

Success rate

• Very high cure rates, often over 95%, especially when performed using staged excision or Mohs with melanoma-specific techniques.

Note: Deeper melanomas that have invaded the dermis or beyond usually require wide local excision and possibly lymph node evaluation.

5. Mohs Surgery for Rare or Unusual Skin Cancers

• Dermatofibrosarcoma protuberans (DFSP): A slow-growing tumor with a high recurrence rate.
• Sebaceous carcinoma: An aggressive cancer often occurring around the eyelids.
• Extramammary Paget’s disease: A rare cancer often found in genital or perianal areas.
• Merkel cell carcinoma: A rare but aggressive neuroendocrine cancer of the skin.

When Mohs is recommended

• When the cancer is in a sensitive location where tissue preservation is vital.
• When the tumor has a high risk of local recurrence, requiring complete margin control.

Success rate

• Varies by cancer type, but Mohs often provides the best chance of full removal while minimizing healthy tissue loss. For example, DFSP treated with Mohs shows recurrence rates as low as 1%, compared to 10–20% with standard excision.

When Mohs Surgery is Not Recommended

While Mohs is highly effective, it’s not the best option in every situation. Here are cases where other treatments may be more suitable:

1. Less serious or superficial skin lesions

• Actinic keratoses, or precancerous lesions, are usually managed with topical creams (e.g., 5-fluorouracil), cryotherapy, or photodynamic therapy (PDT).
• Superficial basal cell carcinomas on the trunk or limbs may respond well to electrodessication and curettage (ED&C), topical treatment, or simple excision.

2. Deep or aggressive cancers that have spread

• Cancers that have invaded muscle, bone, or spread to lymph nodes or distant organs require more than Mohs.
• These cases often involve a multidisciplinary approach, including oncology, radiology, and surgical oncology.

3. Melanoma (except early cases like lentigo maligna)

• Most invasive melanomas are treated with wide surgical excision and sentinel lymph node biopsy.
• Mohs may be used in specific cases of melanoma in situ, and even then, only with trained Mohs surgeons and access to a laboratory that utilizes special stains.

4. Medically fragile patients

• Patients with serious comorbidities or frailty may not tolerate the duration or nature of Mohs surgery.
• Alternatives like radiation therapy, topical treatments, or simple excision under local anesthesia may be safer.

Mohs micrographic surgery is a highly effective, tissue-sparing technique for treating certain skin cancers. With cure rates as high as 99%, it’s especially beneficial for cancers in cosmetically sensitive areas, recurrent tumors, or those with aggressive histologic features.

However, it’s important to remember that Mohs isn’t a one-size-fits-all treatment. Some cancers are better managed with alternative therapies, depending on the tumor type, depth, and patient’s overall health.

If you’ve been diagnosed with skin cancer, consult a board-certified dermatologist or fellowship-trained Mohs surgeon. They can assess your condition and recommend the most appropriate treatment—whether it’s Mohs surgery or another option tailored to your specific needs.

Dr. Chern practices dermatologic surgery and procedural dermatology, including Mohs surgery, laser, vein, and cosmetic procedures. She joined Westlake Dermatology in 2009. Dr. Chern is Board Certified by the American Board of Dermatology and is a member of the American Academy of Dermatology, the American Society for Dermatologic Surgery, the American College of Mohs Surgery, the Texas Medical Association, and the Travis County Medical Association.

Disclaimer: The contents of the Westlake Dermatology website, including text, graphics, and images, are for informational purposes only and are not intended to substitute for direct medical advice from your physician or other qualified professional.