Mohs Surgery (or Mohs Micrographic Surgery) is a technique used to treat skin cancer. The purpose of the procedure is to completely remove all of the cancer while leaving normal skin tissue alone. Mohs Surgery is a highly specialized surgical technique where the surgeon examines all tissue removed for evidence of cancer cells.
What happens during the procedure?
When the tumor appears to be removed the surgeon follows a unique method of confirming it is excised completely.
- The surgeon will remove a thin layer of tissue from the tumor site
- The surgeon then creates a "map" of the tissue to be used as a guide for locating any remaining cancer cells
- The surgeon microscopically examines all of the excised tissue to confirm that the margins of the tumor are clear
If any cancer cells are found in the sections of removed tissue, the Mohs surgeon will then return to the specific area of residual tumor (as noted by the tissue map) and remove another thin layer of tissue. This new tissue will also be examined for cancer cells. This process will be repeated, layer by layer, until the cancer tissue is completely removed.
Once the cancer is confirmed to be removed, the surgeon will determine the best method of closing the wound. A small wound may be allowed to heal on its own or it will be closed with stitches. Mohs surgeons are trained in reconstruction techniques and will select the best option available to minimize scarring.
The Mohs micrographic surgery procedure description and illustration
- Local anesthetic is injected to numb the area.
- Visible cancer is removed by scraping.
- The area of the cancer is removed so that the entire undersurface and skin edges can be examined microscopically.
- Tissue is dyed and a map is drawn so that the tumor found can be located on the patient. Tissue is processed onto microscopic slides.
- The surgeon examines the slides under the microscope. If cancer cells are found, they are marked on the map to guide the surgeon in removing additional tissue.
- Layers of tissue will be removed until no cancer cells are found.
What is the advantage to Mohs Surgery?
This has a very high cure rate for skin cancer because the surgeon confirms through microscopic analysis that the entire tumor is removed during the procedure. It traces the cancer to its root through the mapping process and excises it.
How long does the procedure take?
It will take a few hours and extensive tumors may take longer.
How should a patient prepare for this procedure?
- Get a good nights sleep
- Wash hair and face on the day of the surgery
- Eat a normal breakfast
- Wear clothing that buttons in the front
- Do not wear jewelry or makeup if surgery is to be performed on the face
- Bring a friend or relative to keep you company; a good book or magazine would also be helpful.
To decrease the risk of excessive bleeding during and after surgery:
- DO NOT take aspirin or aspirin-containing products (Bufferin®, Anacin®, Ecotrin®) for 1 week before surgery.
- DO NOT take ibuprofen or naproxen sodium products (Nuprin®, Advil®, Motrin®, Aleve®) for 3 days before surgery. Pain relievers containing acetaminophen (Tylenol®) may be taken.
- DO NOT drink alcohol (including wine and beer) for 24 hours before and 48 hours after surgery.
- DO NOT lift anything heavy or exercise for at least 48 hours after surgery. It is best to resume normal exercise after your stitches have been removed.
The Day of Surgery
Shortly after you arrive, you will be taken to a treatment room where the doctor will review the risks and benefits of Mohs surgery with you and ask you to sign an informed consent form. The area of the skin cancer will be cleaned and a local anesthetic will be injected. The doctor will remove a thin layer of skin surrounding the cancer. Any bleeding will be stopped with an electric machine called a cautery. A bandage will be applied and you will be able to relax while the tissue is processed. It takes about 30 minutes for the layer of tissue to be removed and the bleeding to stop. Preparing the tissue for microscopic examination can take up to 90 minutes. If microscopic examination reveals that tissue still contains cancer cells, the procedure is repeated in the areas where tumor cells were found. The goal is to remove all of the skin cancer and preserve the greatest amount of healthy tissue. Skin cancers can grow deeply and
Care of Postoperative Wound
When it has been determined your skin cancer has been completely removed, your doctor will decide how best to manage your wound. In some cases, the wound is allowed to heal by itself (granulation). In other cases, the wound is repaired with stitches, a skin graft, or a flap. The decision depends on the size and location of the wound. If repair is needed, this usually can be done by a plastic surgeon on the same day, or in some cases, the next day. If your wound will heal by granulation, you will receive written instructions on changing the bandage. This must be done daily for three to six weeks.
After Your Surgery
- Pain Most patients have only slight discomfort. If this occurs, take two Extra-Strength Tylenol® tablets every 4 hours. Continue to avoid compounds that contain aspirin, ibuprofen, and naproxen sodium because they may cause bleeding.
- Bleeding Occasionally, bleeding follows surgery. If this happens, stay calm. Lie down and apply steady, firm pressure over the wound as close as possible to the bleeding area. Keep the pressure continuous for 20 minutes (timed). Do not lift the bandage to check on the bleeding. If bleeding persists after 20 minutes, apply steady pressure for an additional 20 minutes. If bleeding still continues, call RPCI at (716) 845-2300 and ask the operator to page the Dermatology resident on call.
- Swelling, Bruising Swelling and bruising are common, particularly when surgery is performed near the eye. Usually this is not a problem, and the swelling and bruising decrease as the wound heals.
- Drainage All wounds drain during the first week or two and frequent dressing changes are necessary.
- Infection Wound infections are unusual. If you see thick, foulsmelling fluid coming from the wound, call us at (716) 845-2300 and ask the operator to page the Dermatology resident on call. An antibiotic may be necessary.
- Redness All wounds develop a halo of redness that disappears gradually. If the area becomes very red and itchy, you may be allergic to the antibiotic ointment or to the tape. If this develops, call the Dermatology Center at (716) 845-3378.
- Scarring Most surgeries leave a scar. The scar will improve and become less noticeable as time passes.
- Stitches, Skin Grafts If your wound is closed with stitches or a skin graft, keep the area clean, bandaged as directed, and dry until the next clinic visit. If you see foul-smelling fluid coming from the wound, call us immediately, (716) 845-2300, and ask the operator to page the Dermatology resident on call. An infection may be developing and an antibiotic may be necessary.
After the Wound Has Healed
As the wound heals, some tightness and itching are common and usually lessen with time. Itching is often relieved by applying a small amount of plain petroleum jelly on the scar. Tumors often involve nerves, and it may be two years before normal feeling returns. The area may remain numb permanently. Only time will tell. Scar tissue that grows over the wound has many more blood vessels than the surrounding skin. The result is a red scar that may be sensitive to temperature changes. This sensitivity improves with time and the redness gradually fades. If the scar is unacceptable to you, surgical scar revision may be considered. Patients are advised to wait 12 months because the appearance of the scar will continue to improve for up to one year after surgery.
How can I learn if I am a candidate for Mohs Surgery?
To schedule a consultation, please call our referral office at 716-845-3516.