Mohs surgery is a specialized form of skin cancer removal surgery. The goal is to remove all the tumor while saving as much surrounding healthy tissue possible. This minimizes final wound size and leaves the best possible cosmetic result. Skin is removed one stage at a time, while checking the removed pieces under a microscope to evaluate if any skin cancer is remaining. If cancer cells are identified under the microscope, another stage of tissue removal is performed, and the process is repeated. This is done until all the cancer has been removed.
Once the tumor has been completely removed, the surgeon will then determine the best way to close the wound. This can be done by letting the wound heal on its own, suturing the wound up primarily, or by performing a skin graft or skin flap. The best way to close the wound is based on where the skin cancer was located, and the final size of the defect left by the skin cancer removal process.
This procedure is almost always performed in a dermatology office, not in a hospital. The entire process takes anywhere from 2-8 hours. The length of time depends on how many stages is required to remove the entire skin cancer; plus, the time it takes to close the wound. The procedure is done under local anesthesia, meaning an injection of numbing agent will be used so the entire process is pain free. General anesthesia is typically not required and would only be done in a hospital or surgical center for very large or complex cases.
Mohs surgery has a 99% cure rate, making it the most effective way to remove skin cancer. The decision to perform Mohs surgery will be made by a dermatologist, as not all form of skin cancer need Mohs. This decision is based on type of skin cancer, location or skin cancer and size of skin cancer.