Understanding Mohs Surgery
Mohs surgery, named after Dr. Frederic Mohs who developed it in the 1930s, is a highly precise surgical technique used to remove skin cancer. It is considered the gold standard for treating certain types of skin cancers because it offers the highest cure rate while preserving as much healthy tissue as possible. The procedure involves removing the cancerous tissue layer by layer and examining each layer under a microscope during the surgery itself. This allows the surgeon to ensure all cancer cells have been removed before closing the wound, minimizing the need for additional surgeries and reducing the chance of recurrence.
When Dermatologists Recommend Mohs Surgery
Dermatologists recommend Mohs surgery primarily for specific skin cancers and in certain locations. The most common types treated are basal cell carcinoma and squamous cell carcinoma, especially in areas where preserving healthy tissue is critical. It is also used for some other rare skin cancers. The decision to use Mohs depends on several factors.
- Location on the body: Mohs is frequently recommended for skin cancers on the face (especially the nose, eyelids, lips, ears, and scalp), hands, feet, genitals, and other areas where even a small amount of extra tissue removal could affect appearance or function.
- Cancer type and aggressiveness: It is ideal for aggressive or recurrent skin cancers, as the microscopic control during the procedure helps ensure complete removal. For example, a basal cell carcinoma that has come back after previous treatment is often a good candidate.
- Size and borders of the tumor: Larger tumors, or those with poorly defined edges, are harder to fully remove with standard excision. Mohs allows the surgeon to map the cancer’s spread and remove it completely.
- Patients with certain conditions: People with weakened immune systems or genetic conditions that predispose them to multiple skin cancers may benefit from Mohs to maximize cure rates.
How Mohs Surgery Differs from Standard Excision
Standard excision removes the visible tumor plus a predetermined margin of normal-appearing skin (usually 4-6 mm). The removed tissue is then sent to a pathologist, who examines it after the surgery is finished, often taking days for results. If cancer cells are found at the margins, a second surgery is needed. In contrast, Mohs surgery involves the surgeon acting as both the surgeon and the pathologist, examining frozen sections of the tissue in real time during the procedure. This allows for immediate removal of any remaining cancer cells, ensuring complete removal in one visit and sparing healthy tissue.
What to Expect During a Mohs Procedure
A Mohs procedure is typically performed in an outpatient dermatology office. The area is numbed with local anesthesia, and the visible tumor is removed along with a thin layer of surrounding tissue. The surgeon then maps these layers and examines them under a microscope. If cancer is seen, the process repeats-more tissue is removed from only the affected area. Once the margins are clear, the wound is repaired, often requiring a complex closure or reconstruction. The entire process can take several hours, depending on the number of layers needed. Most patients return home the same day with specific aftercare instructions for the surgical site.
Key Benefits and Considerations
The primary benefit of Mohs surgery is its high cure rate, reported in many studies to be around 99% for primary basal cell carcinomas and 94-99% for primary squamous cell carcinomas. It also minimizes scarring and preserves function because less healthy tissue is removed. However, it is not suitable for all skin cancers-melanoma, for example, is typically treated with a different approach, though Mohs may sometimes be used for certain types. The procedure requires advanced training and specialized equipment, so it is not available in every practice. If you are diagnosed with a skin cancer that may be a candidate for Mohs, your dermatologist will discuss whether this technique is appropriate for your specific case.
For more detailed guidance about skin cancer treatment options, always consult a board-certified dermatologist who can evaluate your individual health history, skin type, and the specifics of your lesion. They can determine whether Mohs surgery or another treatment method is right for you.