How the Mohs Procedure Works

How the Mohs Procedure Works 

Mohs surgery is an advanced surgical technique used to treat basal cell and squamous cell carcinomas, removing cancer cells while allowing your doctor to avoid healthy tissue to minimize scarring. The procedure has the lowest recurrence rates, highest cure rates and best cosmetic results of any skin cancer treatment.

The Mohs procedure is done in a clinic office, in stages, under local anesthesia. Using microscopic examination, your Mohs surgeon can pinpoint the areas involved with cancer and selectively remove only those areas, preserving as much normal tissue as possible and minimizing scarring. 

Once the specimen is removed, it will be immediately processed in our on-site pathology lab to evaluate all margins under a microscope. This process will take approximately 60 to 90 minutes. If any of the margins are positive, meaning there are still cancer cells existing, you will undergo an additional Mohs stage to remove the remainder of abnormal cells. This process will continue until the tumor has been completely removed.

Certain types of tumors such as melanoma, sarcomas and other rare tumors, may call for special laboratory staining methods that require overnight processing. In these cases, the surgical area will be bandaged and a follow-up surgery will be scheduled, if necessary, after the results of the lab evaluation.

When the skin cancer has been completely removed, reconstruction options will be discussed with you. The majority of repairs are completed by our Mohs surgeons, but may also be performed by other surgical specialists. The options include, but are not limited to:

  • Allowing the wound to heal by itself (granulation)
  • Closing the wound directly (sutures or stitches)
  • Closing the wound with a skin graft or skin flap
  • Outside closure/repair

As new skin grows over the wound, it may contain more blood vessels than the skin that was removed, particularly as it is healing. This results in a red scar that may be sensitive to temperature changes, but will gradually improve with time. If necessary, we also have a specialized vascular laser that can be used to treat your scar and help your redness go away more quickly.

While Mohs surgery has a very high cure rate, there is always a risk for recurrence of the tumor. It will be important to be regularly seen by your dermatologist or Mohs surgeon in three months, six months, and one year after surgery and each year for the next five years. Studies show that once you develop a skin cancer, you have a higher risk of developing skin cancer in the future. We recommend that you see a dermatologist annually for the remainder of your lifetime.