Mohs surgery is a specialized treatment for the removal of skin cancer. This method differs from other methods of treating skin cancer by using complete microscopic examination of the cut tissue margin of the surgically removed tissue and detailed mapping techniques that allow the surgeon to track and remove all the roots and extensions of the skin cancer.
By combining complete microscopic margin examination with detailed mapping, the Mohs surgeon can identify cancer cells that are not visible on the surface. This allows the surgeon to remove tissue precisely where cancer remains while preserving as much healthy skin as possible.
Cure rates for many appropriately selected primary skin cancers treated with Mohs surgery are very high. The expected rate varies according to the cancer type, size, location, microscopic features, and whether it has been treated previously. Your surgeon can discuss the factors relevant to your diagnosis.
Mohs surgery is most useful in treating skin cancers in cosmetically sensitive areas such as areas of the face, including nose, ears, eyelids and lip; or in treating skin cancers with a growth pattern associated with a high risk of recurrence.
The most common type of skin cancers treated with Mohs surgery are basal cell carcinoma and squamous cell carcinoma. Both tumors grow beyond what is seen on the skin’s surface and can extend along structures such as nerves, blood vessels and scars. With the Mohs technique, these extensions can be followed and removed. Melanoma is not commonly treated with Mohs surgery.
The area around the skin cancer will be cleansed and numbed using local anesthesia (typically the same anesthesia that was used for your biopsy). Once the area is numb, a small layer of tissue is removed. The tissue is carefully mapped and coded by the surgeon and taken to the adjacent in-house laboratory where the technician will immediately process the microscopic slides.
You will have a temporary bandage placed over the wound while you are waiting for the slides to be prepared.
Removing each tissue layer generally takes less time than processing and examining it. Laboratory preparation and microscopic review commonly take 45–60 minutes or longer for each stage. Several stages may be required, and there is no reliable way to predict the exact number before surgery.
Immediately after the cancer is removed, a decision is made for the best method of repairing the wound created by the surgery. Most frequently, the wound is closed with stitches in a side-to-side fashion, by a skin graft, or by a skin flap. Occasionally, when the wound is small enough, no stitches are required, and the wound can heal on its own. Most patients will not require further procedures after the repair of the surgical defect. However, some repairs are completed in two stages, with the second stage occurring two to three weeks after the initial surgery.
Infrequently, a tumor may turn out to be much larger than anticipated. Under these circumstances, another specialist completes the reconstruction and it may take place on the same day or on a subsequent day. It is very rare that reconstruction may require hospitalization.
The length of surgery depends on the extent of the skin cancer. Often surgery lasts approximately a half day or longer. Much of your time is spent waiting for tissue to be processed. Bring reading materials, electronic devices (e-reader, iPad, tablet, etc.). Also, bring a snack or lunch with you on the day of surgery.
Yes. Any surgery that removes skin cancer leaves a scar. Mohs surgery is designed to preserve healthy tissue, and your surgeon will select a repair intended to support both function and appearance. Redness, firmness, swelling, numbness, or lumpiness may occur during healing. Follow the wound-care and scar-care instructions provided for your specific repair; do not begin massage unless your clinical team recommends it.
Many patients have mild to moderate discomfort that can be managed with acetaminophen when medically appropriate. Swelling and bruising are common, particularly around the eyes or mouth. Your clinical team will explain what to expect, which medications are appropriate for you, and when to call the office.
Although your surgeon will remove as little tissue as possible, there are some general risks associated with surgery. Your doctor will discuss these, and any additional problems associated specifically with your situation.