Developed by Dr. Frederic Mohs in the 1930s, Mohs Surgery is the gold standard for treating skin cancer of the face. Mohs surgery involves surgically removing the skin cancer and marking or scaping the tissue to locate any remaining tumor. The cancer is removed layer by layer, observing each layer under a microscope, and continuing until the layer has no cancerous cells. This form of skin cancer treatment ensures that all cancer cells are removed and saves as much of the healthy surrounding skin as possible.

The layer-by-layer factor sets it apart from traditional excisional treatments, which require cutting out the lesion plus a generous margin on all sides. With Mohs surgery, frozen pathology sections are performed immediately to reveal if the margins are tumor free.

Per the Skin Cancer Foundation,

“Mohs surgery is the gold standard for treating many basal cell carcinomas (BCCs) and squamous cell carcinomas (SCCs), including those in cosmetically and functionally important areas around the eyes, nose, lips, ears, scalp, fingers, toes or genitals. Mohs is also recommended for BCCs or SCCs that are large, aggressive or growing rapidly, that have indistinct edges, or have recurred after previous treatment.”

The Mohs Surgery Process

Finding out that you have skin cancer or pre-cancerous growths is incredibly scary, but rest assured that Mohs surgery is minimally invasive and highly effective. With success rates of up to 99% for skin cancer that has not been treated before and 94% for recurring skin cancer, it is typically the first step in treating a non-melanoma cancer. There’s also very little chance of the procedure leaving lasting scars or causing any side effects apart from mild discomfort in the days immediately following your appointment.

Here’s what you’ll experience on the day of your procedure:

  1. You’ll receive a local anesthetic in the treated area, which will completely numb it throughout the procedure.
  2. Your doctor will use a scalpel to remove the skin lesion and a layer of skin underneath the cancer. The layer underneath the lesion will tell the doctor whether there are extensions to the lesion that aren’t visible above the surface.
  3. The wound is temporarily bandaged.
  4. Your skin tissue is immediately taken to an on-site laboratory, where it is sectioned, color-coded with dye, and examined under a microscope.
  5. As the doctor or lab technician observes your skin tissue, they’ll map out any sports where cancerous tissues are still present, like around the edges or on the underside of the sample.  If they have to continue with an additional layer of skin, this map will help them determine the exact area to continue excision and leave the healthy skin intact. The microscope examination must happen in real time, as it’s the only way the doctor can determine whether there are still cancer cells around the lesion’s margin. This process can take an hour or two, but the first excision is all that’s needed in around 40-50% of cases.
  6. If cancer cells are still present, the doctor will repeat steps 2-5 until they are absent from the most recently taken sample.

After the Procedure

Immediately following the Mohs surgery, your surgeon will determine whether your wound is shallow enough to heal on its own. If that’s the case, they’ll provide specific instructions about how to keep the wound clean, the signs of infection to look out for, and how far out to schedule your follow-up appointment. The worst side effect most people experience is mild pain at the surgical site, which an OTC pain reliever can alleviate. However, if you’re experiencing severe pain or the wound won’t stop bleeding, contact your doctor right away.

In other cases, more extensive post-procedure work may be necessary to close the wound or, more rarely, reconstruct the area where the lesion was with a skin flap–healthy skin and tissue near the lesion that is partly detached and used to cover the wound — or skin graft– a healthy piece of skin removed from another area of your body and used to cover larger, deeper wounds.

Final Thoughts

The best thing that you can do for your skin health is to attend yearly skin examinations with a Board-Certified dermatologist and conduct monthly self-exams so you can get any pre-cancerous or cancerous spots removed as soon as possible.

If you don’t yet have your annual skin exam scheduled for 2024, what better time to do so than during Skin Cancer & Melanoma Awareness Month? Contact the skin experts at Advanced Dermatology & Cosmetic Institute for an appointment.