Mohs Micrographic Surgery, developed by Dr. Frederic E. Mohs, is the most advanced and effective treatment procedure available for skin cancer. The procedure is performed by specially trained surgeons who have completed at least one additional year of fellowship training under the guide of a Mohs College member.
With the Mohs technique, physicians are able to identify and remove the entire tumor, while leaving healthy tissue unharmed. This procedure minimizes the chance of re-growth and reduces the potential for scarring. Mohs surgery has a success rate of up to 99 percent, the highest among skin cancer treatments.
Mohs surgery is usually an outpatient procedure, with the patient awake throughout the process, using local anesthesia around the area of the tumor.
The Mohs surgical process involves a series of surgical excisions followed by microscopic examination of the tissue to identify any remaining tumor cells. Some tumors that appear small on clinical exam may have extensive growth underneath normal appearing skin, making it impossible to predict a tumor’s size until the surgery is complete. About half of all treated tumors require two or more stages for complete excision.
Step 1: Anesthesia
The tumor site is locally infused with anesthesia to completely numb the tissue.
Step 2: Removal of visible tumor
Once the skin has been completely numbed, the tumor is gently scraped with a curette, a semi-sharp, scoop-shaped instrument. This helps define the clinical margin between tumor cells and healthy tissue. The first thin, saucer shaped "layer" of tissue is then surgically removed. An electric needle may be used to stop the bleeding.
Step 3: Mapping the tumor
Once a layer of tissue has been removed, a drawing of the tissue and its location to other parts of the body is made, serving as a guide to the location of the tumor. The tissue is labeled and color-coded to correlate with its position on the map. The tissue sections are processed and then examined by the surgeon to thoroughly evaluate for evidence of remaining cancer cells. It takes approximately 60 minutes to process, stain and examine a tissue section
Step 4: Ensuring all cancer cells are removed
If any section of the tissue shows cancer cells at the margin, the surgeon returns to that specific area of the tumor and removes another thin layer of tissue. The newly excised tissue is then drawn, color-coded, processed and examined for additional cancer cells. This process is repeated until the cancer cells have been completely removed.
Step 5: Reconstruction
The best method of repairing the wound after surgery is determined only after the cancer is completely removed. Stitches may be used to close the wound, or a skin graft or a flap may be needed.
Last updated: 22-Jun-09