In 1935, Dr. Frederick Mohs developed a technique for cancer removal known as chemosurgery. Originally, chemicals were applied to the skin during the surgery. The technique has changed and evolved and now chemicals are rarely used. The procedure is now correctly termed Mohs Micrographic Surgery.
Mohs Micrographic Surgery allows for the selective removal of the skin cancer with the preservation of as much of the surrounding normal tissue as is possible. Because of this complete systematic microscopic search for the “roots” of the skin cancer, Mohs Micrographic Surgery offers the highest chance for complete removal of the cancer while sparing the normal tissue. The cure rate for new basal cell and squamous cell carcinomas exceeds 98%. As a result, Mohs Micrographic Surgery is very useful for large tumors, tumors with indistinct borders, tumors near vital functional or cosmetic structures, and tumors for which other forms of therapy have failed. No surgeon or technique can guarantee 100% chance of cure. Other methods of treatment for skin cancer are available.
The Mohs Process
Today the technique of Mohs surgery is performed in the following steps. After local anesthesia, the first step is to remove the visible portion of the tumor. Then a thin layer of tissue is surgically excised from the base of the site. This layer is generally only 1-2mm larger than the clinical tumor. Next, this tissue is mapped and processed in a unique manner and examined under the microscope. Dr. Murphy examines 100% of the entire bottom surface and outside edges of the tissue on the microscopic slides. (This differs from the frozen sections prepared in a hospital setting which examine less than 1% of the tumor margins). The tissue is precisely mapped. If any tumor is seen during the microscopic examination, its location is marked on the map and a thin layer of additional tissue is excised from the precise area involved. The microscopic examination is then repeated. The entire process is continued until no tumor is found.
Preparing for Surgery
Be well rested and eat a good breakfast. Please bathe or shower and wash your hair to minimize your risk of a surgical site infection. Please avoid wearing make-up, perfume, nail polish and jewelry the day of your surgery.
The length of the procedure varies depending on the size and location of the skin cancer and the type of reconstruction to be done. Although the average time is 2-5 hours, you should plan on spending much of the day in our office and we ask that you make no other commitments.
MEDICATIONS: Continue all medications prescribed by your doctor including blood thinners like Coumadin or aspirin. However, if you are taking aspirin, ibuprofen, or herbal supplements without your doctors orders please discontinue them 10 days prior to your surgery appointment. (Including Anacin, Bufferin, Excedrin, Alka Seltzer, Percodan, Advil, Aleve, Motrin, Oral Vitamin E and Ginkgo Biloba). You may take Tylenol if needed for pain. Alcohol will also increase bleeding so avoid alcoholic beverages 48 hours before and after surgery.
TRANSPORTATION: It is helpful if you arrange to have a companion drive you to and from the doctor’s office because the doctor (in rare cases) may give you a mild sedative. You may also be more comfortable with someone to keep you company in the reception area. It is not necessary to have a driver in all instances. We ask that you do not bring more than one companion to your surgery as space in our waiting room is limited.
The Day of Surgery
Appointments for surgery are usually scheduled in the morning. It is a good idea to wear loose fitting clothing and avoid “pullover” clothing. Please do not bring more than 1 companion with you as space is limited in our waiting room. Tylenol may be taken before the surgery in order to reduce discomfort. We will obtain your written consent for the procedure, photographs will be taken, and your blood pressure will be recorded. If you have any additional questions, please feel free to ask them at this time. The doctor will anesthetize (numb) the area of skin containing the cancer by a small local injection. This injection will probably be similar to the one you received for your biopsy. We will be as gentle as we can when administering this. It usually takes about 15 minutes to anesthetize and remove the tissue. After the tissue is removed it will be processed in our laboratory.
Depending upon the amount of tissue removed, processing usually takes an additional 1-2 hours. If you are being treated for melanoma we use state-of-the-art immunostains which usually take 2-3 hours of processing time. Your wound will be bandaged, and you will move to the waiting room while the tissue is processed, stained and examined by the doctor. If the microscopic examination of the removed tissue reveals the presence of additional tumor, the doctor will go back and remove more tissue. Most skin cancers are removed in 1-3 surgical stages, but some require additional stages. The process does not stop until the cancer is completely removed.
We would like to make the time you spend with us as pleasant and comfortable as possible. You may bring reading material to occupy your time, we also have wireless internet available in our reception area. Magazines and beverages will be available in the reception area. If your visit extends through the lunch hour, your companion may bring you a snack or lunch since you are asked not to leave the reception area of our office.
After the skin cancer has been completely removed, a decision is made on the best method for treating the wound created by the surgery. These methods include letting the wound heal by itself, closing the wound in a side to side fashion with stitches, or closing the wound with a skin flap or graft. The best method is determined on an individual basis after the final defect is known. All wound repairs are performed immediately in our Ambulatory Surgical Center while the site is still anesthetized. Very rarely other surgical specialists may be utilized for their unique skills if warranted.
After Mohs Micrographic Surgery
Your surgical wound will likely require care during the weeks following surgery. Detailed written instructions will be provided. Depending on the type of reconstruction performed, some patients will be asked to return to our office in 5-7 days for a wound check. Dissolving stitches are used in our closures so usually no suture removal is required. Rarely, we may need to remove staples especially when working on the scalp.
Most of our patients report minimal pain which responds readily to Tylenol. You may experience a sensation of tightness across the area of surgery. Skin cancers frequently involve nerves and months may pass before your skin sensation returns to normal. In rare instances, the numbness may be permanent. You may also experience itching after your wound has healed. Complete healing of the surgical scar takes place over 12-18 months. Especially during the first few months, the site may feel swollen or lumpy and there may be some redness. Massaging the area starting one month after surgery will speed the healing process.
An indefinite follow-up period of observation is necessary after the wound has healed. Studies have shown that once you develop a skin cancer, there is a strong possibility of developing other skin cancers in the future. Should you notice any suspicious areas, it is best to check with your physician for a complete evaluation. You will be reminded to return to your dermatologist on a frequent basis for continued surveillance of your skin.
Risks of Mohs Micrographic Surgery
Because each patient is unique, it is impossible to discuss all the possible complications and risks in this format. The usual risks are discussed below. Our doctors will discuss any additional problems associated with your particular case. Please understand that these occurrences are the exception and not the rule.
- The defect created by the removal of the skin cancer may be larger than anticipated. There is no way to predict prior to surgery the exact size of the final defect.
- There will be a scar at the site of removal. We will make every effort to obtain optimal cosmetic results. Our primary goal is to remove the entire tumor. Again, Mohs surgery will leave you with the smallest wound thus creating the best opportunity for the optimal cosmetic results.
- There may be poor wound healing. At times, despite our best efforts and for various reasons (such as bleeding, poor physical condition, smoking, diabetes, or other diseases), healing is slow or the wound may reopen. Flaps and grafts utilized to repair the defect may at times fail. Under these circumstances, the wound will usually be left to heal on its own. The scar may be revised at a later date if necessary.
- There may be loss of motor (muscle) or sensory (feeling) nerve function. Rarely, the tumor invades nerve fibers. When this is the case, the nerves must be removed along with the tumor. Prior to your surgery, the doctor will discuss with you any major nerves which might be near your tumor.
- The tumor may involve an important structure. Many are near or on vital structures such as the eyelids, nose or lips. If the tumor involves these structures, portions of them may have to be removed with resulting cosmetic or functional deformities. Furthermore, repairing the resulting defect may involve some of these structures.
- Rarely, wounds become infected (less than 1%) and require antibiotic treatment. If you are at particular risk for infection, you may be given an antibiotic during surgery.
- There may be excessive bleeding from the wound. Such bleeding can be controlled during surgery. There may also be bleeding after surgery. This is usually controlled with direct pressure on the wound.
- There may be an adverse reaction to medications used. We will carefully screen you for any history of problems with medications; however, new reactions to medications may occur.
- There is a very small chance that your tumor may regrow after surgery. Previously treated tumors and large, longstanding tumors have the greatest chance for recurrence.