Download Mohs Micrographic surgery is a specialized technique pioneered

David A. Cowan, MD
MOHS SURGERY – PATIENT EDUCATION
Page 1 of 5
WHAT IS MOHS SURGERY AND WHAT SHOULD I EXPECT?
Mohs Micrographic surgery is a specialized technique pioneered over 50 years ago to improve the cure rates
for treating cancers of the skin. While it is used primarily to treat basal cell and squamous cell cancers, it is also used
in certain instances to treat melanoma, as well as other more rare cancers. Traditionally, skin cancers are treated by
destructive methods (radiation, freezing, scraping and burning, and now with some topical creams) or excision
(cutting out the tissue and sending it to an outside laboratory). These methods all yield cure rates of between 65%
and 94%. However, for large tumors (greater than an inch wide on the body or half an inch on the face), tumors
which were unsuccessfully treated by other means, or are located in cosmetically sensitive areas, there is another
technique (called Mohs Micrographic Surgery) that offers a higher cure rate (in most cases 95% to 99%) while
removing the least amount of healthy tissue.
In Mohs Micrographic Surgery, tissue is removed and processed in a way that we are able to check 100% of
the edges, giving the highest cure rate for any method of treating skin cancers and allowing us to minimize the scar.
The technique originally used zinc chloride paste and tissue had to be processed overnight; however newer
techniques, in which the tissue is frozen, allow us to process and stain the tissue usually within 1 to 2 hours.
The surgery is performed under local anesthesia, which means there is no restriction as to what you can eat before or
on the day of surgery. After numbing the area, we remove the tissue containing the skin cancer, taking a small safety
margin. This margin is usually smaller than what we would take with a standard excision. When we remove the
tissue, it is marked and oriented. This tissue is taken to our lab (located within our office) and processed. We review
the pathology in the lab, checking all of the margins. If any tumor remains, we match up the tissue with the location
on your body, re-anesthetize the area and remove more skin only in the area where the tumor remains. Because we
remove all visible tumor the first time, any remaining tumor is seen only under the microscopic and sometimes it is
difficult to predict how many times we will have to go back to remove all the tumor.
Once the tumor has been removed completely, we will discuss the best way to close the defect. Usually this
will require stitches, but occasionally we will decide to allow an area to heal on its own. In rare instances, especially
for cancers around the eye, we may work with an oculoplastic or plastic surgeon to repair the area, but more than
95% of cases are repaired in our office, on the same day that your skin cancer is removed.
WHY IS IT CALLED MOHS SURGERY?
The technique is named after Frederick Mohs, the surgeon who initially developed the fundamental
techniques that form the basis for the procedure today.
WHAT IS SKIN CANCER?
Skin cancer, by far the most common malignant tumor in humans, is an abnormal growth of cells that expand
in an unpredictable pattern on the skin. The most common types of skin cancer are Basal Cell Carcinoma, Squamous
Cell Carcinoma and Malignant Melanoma - each named for the particular skin cell from which it arises. Basal Cell
Carcinoma and Squamous Cell Carcinomas are commonly treated by Mohs Micrographic Surgery in our office.
Some types of melanoma as well as other less common types of skin cancer may also be treated with Mohs
Micrographic Surgery.
698-348-0713-ID-M
FDERM/MOHSEDU
mohsedu1/mw/gmp/07/12/13
David A. Cowan, MD
MOHS SURGERY – PATIENT EDUCATION
Page 2 of 5
Both Basal Cell Carcinoma and Squamous Cell Carcinoma begin as a single point in the upper layers of the
skin and slowly enlarge, spreading along the surface and downward. These extensions cannot always be seen with
the naked eye. The tumor often extends far beneath the surface of the skin. If not completely removed, both types of
skin cancer may invade and destroy structures in their path.
Although these skin cancers are locally destructive, they do not tend to metastasize (spread) to distant parts of
the body. Metastasis is extremely rare in Basal Cell Carcinoma and usually occurs only with long- standing or large
tumors. Squamous Cell Carcinoma is slightly more prone to metastasize and patients must be seen regularly for
follow-up exams to monitor for any spread of the tumor.
WHAT CAUSES SKIN CANCER?
Excessive exposure to sunlight is the single most important factor associated with the development of skin
cancers. The tendency to develop skin cancers is greatest in those of fair complexion and those who tan poorly. Other
factors, including exposure to certain chemicals, may also be involved in the development of skin cancers.
HOW SHOULD I PREPARE FOR SURGERY?
Eat your usual breakfast. If you normally skip breakfast please eat a snack on the day of surgery. Take all of
your regular medications unless directed otherwise by Dr. Cowan or your physician. If you take any medicine that
thins the blood (see below) we may ask you to consult your doctor to discuss stopping or reducing the dose of
medication. You should NOT stop these medications unless specifically instructed to do so by your physician. Wear
comfortable, loose-fitting clothing that you can get into and out of easily. Often you will need to change into a gown
for surgery. If we are operating on your head, neck or trunk, please wear a button-down shirt, if possible, or a shirt
with a loose collar. If we are operating on your face, please do not apply any makeup to the area, and if you wear
contacts, do not wear them that day, or plan to put them in AFTER the surgery.
If you have any further questions about the day of surgery, please contact our office.
HOW LONG CAN I EXPECT TO BE AT THE OFFICE?
It is difficult to predict how long you will be in the office, as it depends both on how many times we need to
go back to remove more skin cancer (each time we remove skin, it takes 1 to 2 hours to process the tissue) and the
amount of surgery required to repair your defect once the cancer has been removed.
You should plan to be in the office for a minimum of 5 to 6 hours, however most patients are done within 3 to
4 hours from the time we start. It is probably best to leave the rest of day unscheduled so that you allow yourself
time to recover. Most of the day is spent waiting for the lab results, so you should plan to bring some form of
entertainment (a book, work, magazines, or even music). Remember, though, you will have a bandage on while
waiting for the lab and this may prohibit you from wearing your glasses or seeing well enough to read.
WHAT ARE MY ACTIVITY LIMITS AFTER SURGERY?
In part it depends on where on your body we operate and what is required to repair your defect. Unless your
wound is healing on its own (no stitches) you should avoid any strenuous activity for 5-7 days (the blood pressure
elevation related to exercise can lead to bleeding). If you have stitches in an area that will be under tension or
significant movement (like your neck, back, arms, leg) you will need to refrain from heavy lifting or exercise that
will involve that area for at least 2 weeks and possibly longer. We also ask that you do not travel for the first 7 days
after surgery.
698-348-0713-ID-M
FDERM/MOHSEDU
mohsedu2/mw/gmp/07/12/13
David A. Cowan, MD
MOHS SURGERY – PATIENT EDUCATION
Page 3 of 5
ARE THERE ANY HEALTH CONSIDERATIONS OR MEDICATIONS THAT WOULD PREVENT ME FROM HAVING MOHS
SURGERY?
In general patients with diabetes, hypertension, thyroid disease, a history of stroke or heart disease tolerate
skin surgery very well. If you cannot sit or lay flat for more than a few minutes at a time, an alternative treatment
may be more appropriate. If you are concerned about your health preventing you from having surgery or
complicating your surgery please call the office before surgery and ask to speak to Dr. Cowan’s nurse.
PLEASE CALL AND ASK TO SPEAK TO OUR NURSE AT LEAST ONE WEEK BEFORE SURGERY IF:
1. You take antibiotics before dental procedures or other surgeries, have had heart valve surgery, have a congenital
heart defect, have mitral valve prolapse, have had joint replacement surgery, or have undergone placement of other
internal medical devices (pacemakers, AICD’s (automatic defibrillators), arterial or venous grafts, cerebral shunts)
*If you have any of these conditions, please call the physician’s office that performed your surgery or placed the
device and ask them if they would like you take an antibiotic prior to your surgery. Either they can call in the
prescription or we can but please get the name of the antibiotic they would like you to take. If you are unable to
get in contact with them, please call our office at least TWO DAYS before your surgery so that we can call in
antibiotics if necessary.
2. For patients on blood thinners such as aspirin, we generally do not require you to stop these medications unless
we are operating directly adjacent to or on your eyelid. If you want to stop taking them, please contact the doctor
that started you on the medication before stopping it or call our office if you have questions. If you are taking other
medications including: anti-inflammatory medications like ibuprofen, Aleve, vitamin E, garlic supplements, gingko,
and ginseng please stop these at least 1 week before surgery, if you are able.
3. If you have ever been told you have an allergy to an anesthetic used during surgery or dental work please call our
office to discuss this situation with our nurse as further testing may be needed.
WHAT CAN I EXPECT AFTER SURGERY?
You will have some swelling and redness around the wound. This will gradually disappear over 7 to 10 days.
You should plan on wearing a bandage and avoiding strenuous physical activities for one to two weeks. You may
experience a sensation of tightness across the area of surgery. Skin cancers frequently involve nerves and our surgery
often injures the nerves that control sensation. Months may pass before your skin sensation returns to normal and in
some cases, numbness may be permanent. You may experience itching after your wound has healed. Complete
healing of the surgical scar takes place over 12 to 18 months. During the first few months, the site may feel swollen
or lumpy and there may be some redness. Gently massaging the area (starting about two months after surgery) and
keeping the area lubricated with ointment will speed the healing process.
It is important to realize that the edges of your suture line were intentionally elevated so that the edges look
like there is a tunnel under the skin. This is due to the deep stitches, which will eventually dissolve. The sutures are
placed like this because as the skin heals it contracts and we want contraction to go from a raised line to flat, instead
of from flat to depressed or stretched. This lumpiness resolves in almost all patients but takes 2 to 3 months to do so.
Remember that the wound, in the healing stages, will look different and generally worse than the “mature” wound
that has had 6 to 8 months to heal.
698-348-0713-ID-M
FDERM/MOHSEDU
mohsedu3/mw/gmp/07/12/13
David A. Cowan, MD
MOHS SURGERY – PATIENT EDUCATION
Page 4 of 5
BLEEDING
Bleeding is rare. If it occurs, have someone apply firm pressure to the site. If a bulky dressing has been
placed on the wound, it should not be removed. Direct pressure should be applied to the padded wound for 30
minutes, timed by looking at a clock. Do not discontinue pressure to see if the bleeding has stopped until 30 minutes
have elapsed (i.e. don’t peek under the dressing). If the bleeding continues, continue to press directly with an
additional clean gauze pad over the bleeding site for another 30 minutes. If bleeding still persists, call Dr. Cowan or
go to your local emergency room and then call Dr. Cowan. Pressure usually will control bleeding.
PAIN
Mild to moderate pain is normal for a day or two following the surgery, but it generally responds well to oral
pain medication such as Tylenol. Occasionally we will give you another pain medication, usually Tylenol with
Codeine. If you take this medication, you should limit your over the counter Tylenol use. If permitted by your
primary care physician you may use aspirin or anti-arthritis pain medications such as Motrin, Advil or Ibuprofen. If
regular pain medications provide insufficient relief or if the pain increases after three to four days, you should
contact Dr. Cowan.
HOW WILL MY WOUND HEAL?
--HEALING BY SPONTANEOUS GRANULATION (I.E. SECONDARY INTENTION HEALING)
Letting the wound heal by itself is the simplest form of wound healing and has the least post-operative
restrictions in terms of activity. Allowing wounds to heal this way is relatively painless and offers excellent cosmetic
results for many body locations. The main disadvantage is that this takes 3 to 6 weeks before the wound heals
completely. Often you will be left with a lightly pigmented scar which is usually smaller than the original defect.
--CLOSING THE WOUND OR PART OF THE WOUND WITH STITCHES
Using stitches shortens the healing time (usually 1 to 2 weeks) and usually offers excellent cosmetic results,
especially when the scar can be hidden in a line of a facial expression or wrinkling. Sutures generally remain in place
for five to seven days and occasionally up to two weeks, depending on the location. The disadvantage with stitches is
that generally you are more limited in your activities. If you have stitches on your arms, legs, or trunk you have to
refrain from exercise or heavy lifting for a minimum of 2 weeks. Even then, you generally have to limit your
activities and if the area feels strained when lifting/exercising you must stop as you can still break the stitches. Even
after the wound is mostly healed, repeated strain to the area can stretch the scar.
--CLOSING THE WOUND WITH SKIN GRAFTS, FLAP REPAIRS OR OTHER RECONSTRUCTIVE PROCEDURES
For wounds that are too large for primary closure (a straight line of stitches), Dr. Cowan may repair the
wound with a flap or skin graft. Occasionally, an additional surgery to correct cosmetic or functional problems may
be needed (including dermabrasion or scar revision). Dr. Cowan will discuss these options with you after the cancer
has been totally removed.
698-348-0713-ID-M
FDERM/MOHSEDU
mohsedu4/mw/gmp/07/12/13
David A. Cowan, MD
MOHS SURGERY – PATIENT EDUCATION
Page 5 of 5
MISCELLANEOUS PRE-OPERATIVE CONSIDERATIONS, LIMITATIONS AND EXPECTATIONS







When scheduling, please take into account that your activities after surgery should be limited. We would
prefer that you do not make any out of town travel plans for a minimum of one week after surgery (two or
three day minimum).
It is rare that you will experience bleeding or infection after surgery, but if you do we would like to be able to
see you in the office. If this is not possible, please let us know at the time of surgery.
Depending on the size and location, we may ask you not to bend over or lift anything over 10 lb for the first 2
weeks.
If stitches were used for an area on your arm or leg you must wait at least 2 weeks before resuming light
activities with that extremity, and you may need to abstain from strenuous use of the affected limb for up to 6
to 8 weeks depending on the location and number of stitches needed.
If the area to be operated on involves your nose, cheek, or is near you eyes we often need to place a bulky
bandage over the area which may prevent you from wearing your glasses until the dressing is changed the
next day. If you need glasses for driving you should plan to have someone drive you home.
Although you may shower after 24 hours and get your wound wet on a daily basis, we ask that you wait at
least 7 days before going into a pool, or the ocean.
After operating on the foot, we usually recommend using crutches for 3 to 7 days to limit strain to the area.
We look forward to taking care of you on your surgery day. If you have any questions before, during, or after
your surgery do not hesitate to call the office and ask to speak to Dr. Cowan or his nurse.
David Cowan, MD
Lisa Henderson, PA-C Sheri Rolewski, CRNP and the Staff of BHS Dermatology
Benbrook Medical Center I
102 Technology Drive Suite 240
Butler, Pennsylvania 16001
Phone: 1-877-661.3376
Fax: 724-482-2212
BHSdermatology.org
Phone: 1-877-661-3376
Fax: 724-431-0252
** Not Part of the Patients Permanent Medical Record – Interoffice Use ONLY **
698-348-0713-ID-M
FDERM/MOHSEDU
mohsedu5/mw/gmp/07/12/13