A Guide to Mohs Surgery


Cancer-curing surgery
Mohs micrographic surgery is a developing type of skin cancer surgery that is generating impressive cure rates. About 99% of basal cell cancers and 95% of squamous cell cancers are cured with Mohs micrographic surgery. The American College of Mohs Surgery has awarded fellowship training to a number of leading physicians for this highly specialized “precision surgery,” increasingly recognized as a powerful tool to stop cancer in its tracks – literally, at a cellular level.

Not only does Mohs surgery increase the chances of completely removing cancer cells, it also minimizes the loss of normal surrounding tissue, offering better and Mohs after surgerysimpler
post-surgical reconstruction options. If your doctor recommends Mohs surgery, it is because it is a proven and effective treatment.

As a Mohs micrographic surgeon, I offer this guide to Mohs surgery from a practical perspective.

Once you and your doctor have determined that Mohs surgery is appropriate, your first concern should be about the location at which the procedure will take place. Ensure that the surgery will be performed in an accredited outpatient surgical facility, using sterile techniques and local anesthesia.

Mohs surgery is a relatively simple method. After the anesthesia has been injected and the area is numb, the surgeon removes the visible portion of the tumor. Then, a small layer of skin (2–3 millimeters) is removed and microscopically examined to ensure that “nests” of tumors too small to be seen with the naked eye do not remain. 

If more cancer is observed, the surgeon removes slightly more skin, but only in the precise area where microscopic tumor was visualized. This meticulous real-time “removal/analysis” cycle helps Mohs surgeons zero in on troublesome cells and use precise surgery to eliminate them. 

Once the tumor is completely removed, reconstruction begins, which is yet another distinct surgical expertise. Some Mohs surgeons have received additional reconstructive training in cutaneous flap and graft repair techniques. 

It is impossible to know the full extent and exact size of the skin cancer prior to its removal, and that information will determine if consultations with other reconstructive physicians is appropriate. If a special repair is necessary, your surgeon will discuss recommendations with you and will assist in consulting with the appropriate plastic reconstructive surgeon.

The Mohs surgical approach – managing the process from complete cancer excision to complete cosmetic restoration – benefits skin cancer patients by its efficacy (ie, how effective it is) and by requiring fewer surgeries. The complete removal of your tumor and your final cosmetic outcome is of utmost importance to your Mohs surgical team.

Your Mohs surgery
You will be admitted to a surgical center – a suite of private rooms with a special operating chair, similar to a dentist’s office. Sometimes, family members are allowed to remain in the room during the procedure, sometimes not. Prior to surgery, you will have the chance to talk with your medical team.

Once you’re comfortably settled, a small amount of local anesthesia is injected into the skin surrounding the tumor. The Mohs surgeon uses precise micrographic tools to completely remove the tumor, which usually takes only a few minutes. After that, a temporary bandage is placed over the area, and the first surgery period is over. Family members are generally allowed to visit at this time. While you wait, a specially trained histotechnician will process the removed tissue and make what is called a frozen section. 

Frozen sections are cut, inked, and stained in a special manner that allows the physician to map the precise location of any remaining tumor nests. If tumor cells remain, the temporary bandage will be removed, more local anesthesia will be injected, and another small layer of tissue will be cut away. Each time a layer is excised, it will take 5–10 minutes, but the frozen section may take up to an hour to generate and interpret.  

Once the skin cancer has been successfully removed, the physician will discuss reconstructive options with you, including if it would be beneficial for another surgeon to repair the wound. Usually, however, the resulting defect can be repaired right then and there. If so, more anesthesia is injected, the skin is sutured together, and antibiotic ointment and a bandage is placed on the wound.

Before you leave the surgery center, it is common for a nurse to review a set of written instructions about when and how to change the bandage. It is not usually necessary to take pain pills or antibiotics after Mohs surgery, but occasionally these are given based upon your medical history, or when the procedure has been unusually long or complicated.  

Preparing for Mohs surgery
Shower and shampoo the morning of your surgery. (You may need to keep the surgical site clean and dry for several days afterward.) Dress comfortably, keeping in mind where the bandage will be, postsurgery. For example, if the procedure is on your nose, a pullover sweater may be difficult to remove without affecting the bandage, so a cardigan may be a better choice.

Eat normal meals before your surgery, unless your doctor advises otherwise. Bring a snack and some light reading material to your appointment, as this may help you pass the time while you are waiting for the frozen sections. A friend or family member is not usually required to drive you home, but it is nice to have someone with you in case you need some help. 

Take all of your regular medications, unless your doctor tells you not to. Additionally, it is helpful if you can bring all of your medications, in their original bottles, to your appointment so that your doctor knows everything that you are taking. 

If you take aspirin, ibuprofen, naproxen, Coumadin, Plavix or other blood thinners, be sure to discuss this with your physician at least 2 weeks prior to your procedure. Do not stop taking these medications without talking to your doctor first. Some over-the-counter medications may also increase your risk of bleeding. Let your doctor know if you take garlic, ginger, ginkgo, ginseng, dong quai root, bilberry, chondroitin, vitamin E, niacin, or fish oil tablets (omega-3 fatty acids). 

It is also helpful to avoid alcohol from 1 week before surgery until 1 week after. If you must smoke, please limit the amount and abstain for at least 2 hours before the procedure.

What to expect after Mohs micrographic surgery

The area should remain relatively immobile and elevated to reduce swelling and pain. A cold compress can help reduce swelling. The treated area may be tender when the numbing medication wears off. Acetaminophen is usually used for pain, as it does not increase your risk of bleeding. If acetaminophen doesn’t handle your pain, call your doctor. Pain may be a sign of a complication such as an infection or hematoma (blood clot).

The bandage should stay in place and remain clean and dry. Your doctor will provide written instructions about caring for the wound, which generally include cleansing the area once or twice daily with warm water and a gentle soap.

Plan to stay in town for at least 7 days following your procedure in case there is a complication. You should adjust your activity level downward – in other words, no heavy lifting or strenuous exercise. Avoid smoke and secondhand smoke, as it slows healing.

If you are not happy with the results
If your surgery occurred on a highly visible area, it is natural to be concerned about possible postoperative scarring. If there is scarring, I first advise patience. As the skin heals, scars often fade.

If the scar does not fade, there are many techniques to improve surgical scars, including injections, dermabrasion (a sanding down of the tissue), lasers, and scar revision surgery. Usually these are not undertaken for several weeks to months after the first surgery because the skin will continue to heal, and it may be possible to avoid a reconstructive procedure all together if you give it some time.

Choosing a Mohs micrographic surgeon
Mohs surgery is not a procedure that requires special certification to perform, and the quality of the procedure will be greatly influenced by the education and training of your surgeon. There are actually very few quality checks and guidelines currently in place. Often, the doctor who performs your biopsy will have some recommendations. 

You can ensure that your surgeon has received at least 1 year of an accredited fellowship training in the area if you log on to the Mohs College Web site at www.mohscollege.org. Most Mohs surgeons have not had this specialty training, but those who have and wish to remain members of the college must meet certain quality assurance standards. Mohs surgeons can be from any specialty, but most are dermatologists, plastic surgeons, and otolaryngologists. 

American Academy of Dermatology               
American Society for Dermatologic Surgery       
American College of Mohs Surgery           
Skin Cancer Foundation

Published on 07/13/2011 | Last updated on 10/18/2018