Mohs: Micrographic Skin Surgery

What are the advantages of Mohs?

Mohs surgery is the most effective and advanced treatment for skin cancer today. With Mohs the tumor can be removed with microscopic precision, so it is possible to confirm its complete treatment at the time of surgery with the removal of a minimal amount of healthy tissue. Mohs surgery not only conserves healthy tissue, it also offers the highest cure rates for most types of skin cancer. In fact, most studies show a cure rate between 97% and 99.8% for primary basal cell carcinoma, the most common type of skin cancer.

What is the history of Mohs?

This technique for treating difficult skin tumors was originally developed by Dr. Frederic Mohs and later refined by Drs. Stegman and Tromovitch. Originally the treatment was referred to as Mohs Chemosurgery, but is now called Mohs Microscopic Surgery for its reliance on the surgeon’s microscopic examination of frozen tissue specimens

How is Mohs surgery performed?

A cancerous tumor is excised (almost always with a local anesthesia) with a small margin of additional skin. The entire specimen is then frozen and prepared for the microscope where the complete margin is then checked for any evidence of remaining tumor. A clear margin is usually confirmed, but if any tumor is seen at the edge of the excision, its location is precisely determined with the use of tissue maps and dyes. An additional margin of skin is then removed and also examined. Complete treatment usually requires one or two stages, but in large or difficult tumors, more stages may be required. Generally, the entire treatment can be completed in one visit to the office.

What skin cancers require Mohs?

Skin tumors with a higher risk of recurrence, those that may have already recurred, and those located in critical areas such as eyelids, nose, lips and ears where tissue conservation is especially important are generally considered for Mohs surgery. Occasionally, a biopsy will show a more aggressive type of skin cancer best treated by the Mohs technique.

Will there be much pain?

Your treatment will be carried out under local anesthesia (lidocaine) which blocks all pain. There will be some pain associated with the initial injection of anesthetic. There will also be mild to moderate pain beginning several hours after surgery and usually resolving over 24-48 hours. Acetaminophen is usually adequate for pain control. Applying ice packs to the surgical site, (placed on top of the bandage) is especially helpful for pain, swelling, and bruising.

Why not use Mohs for all skin cancer?

This type of surgery can be relatively complex and time consuming. Most small, non-complicated cancers are best removed by more economical surgical excision, offering good cure rates.

Will there be a large skin defect?

This depends entirely on the size and extent of the cancer removed. If the tumor has spread extensively, the defect may be sizeable.

How do you repair the defect?

This will be addressed immediately after complete removal of the tumor is confirmed, almost always on the same day. Sometimes the defect can be closed directly with sutures, sometimes a reconstructive procedure utilizing a skin flap or graft is utilized, and sometimes the defect will heal nicely without any further treatment. Rarely, a staged repair requiring several additional procedures spread over weeks to months may be required. In almost all cases, the repair will be accomplished in our office, but in some cases it may be necessary to refer you for additional treatment by another specialist.

What should I expect on surgery day?

After the Medical Assistant brings you to the treatment room, photographs may be taken, the skin is cleansed and the numbing medicine is injected. Usually you will be fully awake, but if you wish some medication for sedation, this can be arranged—provided you will not be driving. After the area is numbed, the tumor will be removed and sent to the laboratory to be prepared for examination. This usually takes only a short time and a temporary dressing will be applied and you will be returned to the waiting area. The removed tissue will then be processed and examined. If more tumor removal is required, the process is repeated. Once we are sure the entire tumor has been removed, we will discuss what kind of repair, if any, is needed. This will usually be performed at that time. After the repair, a dressing will be applied. You will then be given instructions for post-procedure care and will be discharged to go home

Will the cancer return?

This may vary somewhat depending on size, location, and history of the tumor, but for basal cell carcinoma, 95-99 of 100 patients are cured.

What are the risks?

There are risks associated with any form of surgery. Because Mohs surgery is performed in an outpatient setting with local anesthesia, it is safer than most forms of surgery. Bleeding, infection, or nerve injury can occur with any form of skin surgery. Fortunately, these are rarely a problem with Mohs surgery. There will be a scar after surgery. We use reconstructive and plastic surgery techniques to minimize and hide scars as much as possible. Scars mature and fade over time. On rare occasions a surgical revision can be performed to improve scars.

What happens if I do nothing?

Most BCC (basal cell carcinoma) and SCC (squamous cell carcinoma) tumors grow slowly so things may seem fine for awhile. However, the tumor will enlarge insidiously and eventually produce problems such as pain and bleeding. With time, most tumors gradually burrow deeply within the body and, if neglected, some can spread to distant sites

Will it be expensive and do I need to pay on the date of service?

You will not be asked to pay on the day of your treatment. The only exception to that is if you are uninsured and will not be returning to our office for follow-up care. We will help in billing your insurance and participate with most plans—ask our office staff about your particular plan. If you have no insurance, we can arrange any reasonable payment schedule for you and offer a discount for full payment. Relative to other treatments such as radiation or hospital surgery centers, Mohs is not costly. Depending on the complexity of the tumor, costs may vary from approximately $700-$2,000. Reconstructive procedures are considered in addition to the Mohs surgery and vary depending on the procedure but are considerably less costly when we are able to perform them in the office rather than a surgery center or hospital. If you have any further questions, we will happily attempt answers either before or on the day of your surgery.

How do I prepare for my surgery day?

Avoid all aspirin (Empirin, Excedrin, Bayer, Anacin, and others) for at least ten days prior to surgery. Ibuprofen and Aleve should be avoided for two days—these products will increase bleeding complications. Tylenol (Acetaminophen) is acceptable. Eat a normal breakfast. You may be in the office most of the day. Wear comfortable clothing; a shirt or blouse that buttons rather than a pullover is best. Since you may spend most of the time waiting for the laboratory preparation and examination of specimens, you may wish to bring a good book. If you are easily fatigued, are expecting a large surgery, or if you require a sedative for anxiety, please arrange for a ride to and from our office.


What care is required after surgery?

The dressing may be left in place 1-5 days depending on the type of repair. During this time, the area must be kept absolutely dry. Immediately after removing the dressing, there may be some blood on the skin—this is best removed with hydrogen peroxide or mild soap and water. After dressing removal, the area should be washed gently several times daily and an antibiotic ointment applied. Sutures are generally removed in 5-7 days.