Mohs Micrographic Surgery from Idaho Dermatologic Surgery & Laser Center in Southern Idaho


What is Mohs Micrographic Surgery?

Mohs Micrographic surgery is a surgical treatment for skin Cancer that offers a very high rate of cure, up to 99%. It was developed approximately 50 years ago by Fredrick E. Mohs, MD, a general surgeon at the University of Wisconsin. It is an advanced treatment for skin cancer in which the physician acts as the surgeon, the pathologist, and the reconstructive surgeon.
The basic procedure involves surgically removing the visible skin cancer, processing that tissue, and then looking at all the edges of that tissue under the microscope to make sure that all the skin cancer has been removed. If any skin cancer cells are visible under the microscope, the Mohs surgeon goes back to the patient and removes more skin from the edge that was positive. This tissue is then processed and checked under the microscope, and the procedure is repeated until the edges are free of cancer cells. The actual processing involves drawing a map of the tissue with its orientation to the patient so that any cancer cells found microscopically can be located exactly on the patient. The tissue is then frozen, and thin slices are taken from the outside edges with an instrument called a microtome. These slices are carefully placed on microscope slides and then stained with tissue dye to aid in the visualization of the cells. The surgeon then examines the slides under the microscope to look for cancer cells.
The process of Mohs Micrographic Surgery is time consuming and requires highly specialized personnel. Each time a portion of skin is taken from the patient, it takes about an hour for the tissue to be processed by the histotechnologist. Once all the cancer cells have been removed, the wound can then be reconstructed. The amount of reconstruction necessary will depend on the size of the wound and where it is located. Please see the section on "How wounds are managed after surgery."
For more detailed information on Mohs Surgery please visit the Patient Information section the following website:

I am scheduled for Mohs Surgery, now what?

Your physician has recommended this technique because Mohs micrographic surgery has been proven to be a highly successful form of treatment for your type of skin cancer.
Now that you have an appointment for surgery, it is important that you have any questions answered that you might have about this procedure.
The information presented on this website is designed to help answer these questions, along with providing information on skin cancer and preventive measures you can take to decrease the possibility of developing skin cancers in the future. Please read through this information and call if us if you have any questions before your surgery.
The phone number is (208) 327-9521

If you need to change your appointment, if possible, please notify us at 3 days in advance

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How to prepare for your surgery

No real preparation other than a good night's sleep is required. Eat a light breakfast on the day of surgery. If you are currently taking medication, continue as usual unless directed otherwise by your physician. If you are taking aspirin or any medications containing aspirin (such as Bufferin, Anacin or Excedrin), unless instructed by Dr. Cottingham, these medications should be discontinued at least one week before surgery. This is because aspirin tends to prolong bleeding during the operation. Also, eliminate pain medications such as ibuprofen, Advil, Nuprin, Motrin, Aleve and other non-steroidal anti-inflammatory medications including many prescription pain medications and arthritis pain medications for at least three days before surgery. If you are unsure whether a medication you are taking falls into this category, ask your doctor, or call us. If you need a pain reliever in the interim, you may take acetaminophen, which is found in Tylenol.
It is best to wear a shirt that buttons down the front. No makeup or jewelry should be worn if surgery is to be performed on your face.
Bring a good book or magazine with you since you will spend most of the day in the waiting room while the microscope slides are prepared and interpreted. We recommend that you bring someone with you to help pass the time and to drive you home after your surgery. We do offer mild sedative medications for those individuals who may be more anxious than average about the procedure, but you must have someone to drive you home.
We suggest that you bring a lunch on the day of surgery, and plan on being in our office the majority of the day.

What to expect on the day of surgery

Shortly after your arrival, you will be taken to one of the treatment rooms, where the doctor or a member of her trained staff will use a needle to inject local anesthetic to numb the tumor area.
The doctor will remove a thin layer of skin surrounding the cancer. After this has been done, any bleeding will be stopped with an electric needle. This process is called cauterization. You are then bandaged and can return to the waiting room. By this time, the removed tissue will be in our laboratory. There, it is cut, dyed, and made into microscopic slides. It usually takes 20-30 minutes for the layer of tissue to be removed and the bleeding to stop. However, it takes about one hour for the tissue to be prepared into microscopic slides for examination. During this time you may read your book or magazine, or visit with your friend or relative who has accompanied you. We suggest that you bring a lunch, as you will most likely be with us into the afternoon on the day of the surgery. There is also a cafeteria in the hospital adjacent to our office.
If examination of the microscopic slides reveals that your tissue still contains tumor cells, the procedure will be repeated. Further tissue is removed only from the areas where tumor cells were found. The goal is to remove all of the skin cancer while preserving the greatest amount of healthy tissue. However, skin cancers can grow deeply and develop roots extending beyond the area that you actually see. As a result, the final size of the surgical incision will be determined by the extent of the tumor.
The average number of layers of tumor-involved skin which must be removed is two to three. However, you may require more than this before your skin cancer is completely removed. Fortunately, this can usually be done in the course of a single day. When surgery is completed, a decision will be made about the best way to manage your wound.

How Wounds Are Managed After Surgery

Once it has been determined that your skin cancer has been completely removed, we will decide the best way to manage the wound created by surgery. In some instances, the wound should be allowed to heal by itself; this is called "healing by granulation." In other cases, the wound needs to be repaired by closing the edges side to side with stitches, or a skin graft or flap. The decision will depend on the size and location of your wound. If a repair is needed, this usually can be done the same day, or in some cases, the next day.
If your wound is left to heal by itself, you will need daily bandage changes for three to six weeks. You will be given written instructions that describe how to change your bandages.
If you have stitches, the will usually need to be removed in 1-2 weeks depending on the location. You will be given verbal and written instructions that describe how to care for the area.

What to expect after your surgery

PAIN. Most patients do not have severe pain, but experience slight discomfort. If this occurs, we suggest you take two tablets of Tylenol every four hours. Avoid compounds containing aspirin, such as Anacin, Bufferin, and Excedrin; as well as products containing ibuprofen, such as Advil, Nuprin, and Motrin. These compounds may cause bleeding. For larger reconstructions, your doctor may prescribe a stronger pain medicine. Please let her know if you have any allergies to any pain medicines.
BLEEDING. Occasionally, bleeding follows surgery. If this happens, do not become alarmed. Lie down and place steady, firm pressure over the wound as close as possible to the bleeding area. Apply the pressure continuously for 20 minutes. If bleeding persists after 20 minutes of steady pressure, apply pressure for an additional 20 minutes. If bleeding still continues, call our office at (208) 327-9521 or go to the nearest hospital emergency room.
SWELLING. Swelling is very common following surgery, particularly when it is performed near the eye. All wounds swell a little. Usually this is not a problem and the swelling diminishes as the wound heals. Use of ice packs and elevating the affected area can be helpful.
DRAINAGE. All wounds will drain to some extent during the first week or two. This is why frequent dressing changes are necessary.
INFECTION. Infection of the wound is unusual. However, if you notice thick, foul-smelling fluid coming from the wound, call our office immediately. An increase in redness, swelling, and pain the first 2 days after surgery can indicate an early infection and you should call our office. An antibiotic may be necessary.
REDNESS. All wounds will develop a halo of redness which disappears gradually. If the area becomes extremely red and itchy you may be allergic to either the ointment or tape. Call our office if this condition develops.
SCARRING. All surgeries leave a scar. However, your scar will improve and become less noticeable as time passes.
STITCHES AND SKIN GRAFTS. If we close the wound with sutures (stitches) or place a skin graft, you should keep the area clean until the next visit in accordance with the written wound care instructions you received. If you misplaced your wound care instruction sheet, it is available on our website: . If you experience foul smelling fluid coming from the wound, call our office immediately at (208) 327-9521, as an infection may be developing.

What to expect after the wound has healed

You may experience some tightness as the wound heals. This is normal and usually lessens with time. Patients also commonly experience some itching after their wounds have healed. This is often relieved by rubbing a small amount of petroleum jelly on the scar. Frequently, tumors involve nerves, and it may take up to a year or two before normal feeling returns to an area. Sometimes the area remains numb permanently. Only time will tell.
The scar tissue that grows over the wound contains many more blood vessels than the skin that was removed. This results in a red scar that may be sensitive to temperature changes. This sensitivity improves with time and the redness gradually fades.
Sometimes the scar is unacceptable to the patient and the patient's family. If this is the case, surgical scar revision may be considered. However, we usually advise patients to wait 6-12 months before having the scar revision performed. This is because the scar continues to improve in appearance and becomes less conspicuous up to one year after surgery.

Follow-Up Visits

Once your surgery is over, regular skin exams by your dermatologist are important. These visits can help with early detection and treatment of any new skin cancers that may develop as well as the rare recurrence of the skin cancer that was treated.
As a person who has had skin cancer, you are at risk of developing others in the years ahead. You should be seen at least once every year by your dermatologist. If you notice any suspicious areas on your skin between visits, it is best to check with your physician to see if a biopsy is needed.
Please read the Skin Cancer Information on this website.
Please call our office for to schedule a consultation: (208) 327-9521.