Mohs Micrographic Surgery

What is Mohs surgery?

Mohs surgery is the gold-standard treatment for skin cancers with high-risk features (i.e., located on the head and neck or those with aggressive growth patterns). This procedure allows removal of the smallest amount of tissue and ensures complete removal of the lesion as the pathology is performed on the same day. Mohs surgery is indicated in cosmetically and functionally sensitive areas where healthy tissue conservation is critical.

Since its development in the 1930s, Mohs surgery has become recognized as the most precise and definitive treatment for skin cancer, yielding success rates up to 99%. Compared to traditional skin cancer treatment techniques, Mohs micrographic surgery is more effective because it comprehensively evaluates the tissue surrounding the cancer on a microscopic level.

Why is Mohs surgery performed?

Mohs surgery is used to treat:

• Basal cell carcinoma
• Squamous cell carcinoma
• Melanoma (slow Mohs or staged excision)
• Other forms of skin cancer

Your doctor may choose this method to address skin cancer that is:

• Cosmetically/functionally sensitive areas such as head and neck, hands, feet, shins
• Large (i.e., > 2 cm)
• Has aggressive pathology (i.e., infiltrative, poorly differentiated)
• On a person with a suppressed immune system such as after an organ transplant, lymphoma
• Recurring after previous treatment or radiation

Mohs Procedure: What to Expect

Mohs surgery takes place in an outpatient setting, usually lasting 2 to 4 hours on average. Local anesthetic is used to numb the area, and the skin cancer is precisely removed in layers.

After each layer of tissue is removed, the specimen is frozen, sliced into very thin sections and processed onto glass slides by a Mohs histotechnician, a professional who is specially trained in preparing these slides. This process typically takes approximately one hour per stage.

The Mohs surgeon then examines the slides under the microscope to assess the extent of the skin cancer and identify any microscopic roots. If tumor cells remain at any of the margins, an additional tissue layer is taken at the area of involvement. This procedure continues until the tissue is cancer-free, which spares the maximum amount of healthy surrounding tissue.

Once the skin cancer has been completely removed, the defect is repaired on the same day. The reconstruction is designed to optimize cosmetic appearance of the surgical site. Dissolving stitches are commonly used in low tension areas, and non-dissolving stitches are used in areas with higher tension or movement. The Mohs surgeon will discuss the best options for each individual case.

Care After Mohs Surgery

The Mohs surgery team will bandage the surgical site, provide wound care instructions, and schedule follow-up to ensure a smooth healing process. After Mohs surgery, it is important to avoid strenuous activities for one to two weeks depending on the site and size of the surgery. Our goal is to provide complete care from start to finish of each skin cancer surgery!