Mohs micrographic surgery is a special technique to remove skin cancer. Mohs surgery is unique because it allows the surgeon to map and remove not just the visible parts of a skin cancer, but also the roots that can only be seen under the microscope. When used to treat basal cell carcinoma and squamous cell carcinoma, Mohs surgery has the highest cure rate of any treatment. This technique also allows the Mohs surgeon to spare normal skin to minimize scarring.
The surgery is done in stages, though all during the same appointment with the doctor. After the site is cleaned and anesthetized, the Mohs surgeon will remove the visible portion of the tumor together with a very small margin of normal skin. The tissue is then processed in the laboratory and viewed under the microscope by the Mohs surgeon. In approximately one hour the Mohs surgeon will have determined whether the tumor is completely removed or whether it is necessary to remove additional tissue. The Mohs surgeon is able to carefully map out the area where the tumor remains and will only remove additional skin in the areas where the margin shows tumor. This process is repeated as many times as necessary by the Mohs surgeon to ensure that the tumor is completely removed.
Once the margins are clear the surgeon will determine which repair will give the optimal and functional cosmetic outcome to restore normal architecture and function. In some cases the best repair is a simple straight line while in other cases the best repair may require shifting and re-draping skin (flaps) or borrowing skin from a distant site such as the skin over the collarbone or the skin fold in front of the ear (grafts). Often stitches are required to create the repair that will ultimately give the best appearance once the site is healed.