Dr. Frederick Mohs, Professor of Surgery at the University of Wisconsin, developed this unique form of surgery in the 1930s. Since that time, the technique has been refined and advanced so that, today, it is offered in most major medical centers throughout the country. Its wide acceptance stems from the fact that it can offer a cure rate of approximately 98 percent.
The surgery is performed on an outpatient basis except in rare circumstances. Local anesthesia is used to numb the area around the skin cancer. Once the area is numb, as much of the tumor as possible is scraped off using a special instrument. A thin layer of skin around and under the tumor is then removed. It is marked, frozen and stained so that it may be examined under the microscope. If tumor is found, it may be necessary to repeat the process of removing another layer of skin, preparing it for the microscope and examining it. These steps will be repeated until no tumor is detected.
Each stage takes approximately one hour. While the tissue is being processed, patients have a pressure bandage applied, and are free to read, talk with a companion if they brought one, rest or work on their laptops. Since we cannot determine beforehand how many stages an individual may require, it is necessary to assume that patients undergoing Mohs surgery will spend at least several hours with us. In rare instances, removal of the tumor takes the whole day.
The major advantage of this technique is that, by using the microscope to guide us, we remove only the tissue that the tumor has already invaded, sacrificing little of the surrounding normal skin. This is important if the cancer is close to vital structures, especially on the face. Any procedure will leave a scar, but by preserving the maximum amount of healthy skin and creating the smallest possible defect while completely removing the tumor, the best cosmetic result will be more easily achieved.
Since we cannot predetermine the size of the cancer, it is difficult to discuss how the wound will be repaired until the surgery is completed. There are several ways of fixing the skin:
- to let it heal by itself
- to stitch the wound together
- to create a graft or flap, which involves moving healthy skin from elsewhere to cover the defect.
Once the tumor is completely removed, we will discuss with you the best options for repair. In most cases, it will be done immediately following the removal of the tumor. If you have any special concerns/requests regarding repair, please let us know as early as possible before your appointment.
Mohs surgery is performed by a team specially trained in this technique. The team includes the physician, the nurse, the medical assistant and the technician who is responsible for preparation of the tissue for microscopic examination.