Mohs Micrographic Surgery

Mohs micrographic surgery, an advanced treatment for skin cancer, offers the highest potential for cure – even if the skin cancer has been previously treated.

Brian Pucevich, MD is the fellowship trained MOHS surgeon at Dermatology Associates of Western Pennsylvania. The Mohs surgery technique combines surgical removal of the cancer with immediate microscopic examination of the removed tissue to identify cancerous areas. Mohs surgery not only has the highest cure rate of all treatment methods, but it creates the smallest possible surgical defect, allowing for the best cosmetic results (less scarring).

Mohs Micrographic Surgery Advantages

Mohs Micrographic Surgery Advantages

1. Mohs micrographic surgery offers the highest potential cure rate for removal of skin cancer:

99% for primary tumors
95% for recurrent tumors

This high cure rate is related to horizontal sections taken from the bottom and sides of each tissue block examining 100% of tissue margins.

This replaces the standard histologic bread-loaf sectioning or four-quadrant sectioning where less than 1% of tissue margins are examined.

2. Healthy tissue is spared leading to smaller scars as repairs are less complicated.

3. The complete removal of the skin cancer and reconstruction when indicated can often be completed in one single day, as the procedure is performed in Dr. Pucevich’s office and pathological examinations are conducted immediately.

4. Unless otherwise indicated, the procedure is performed under local anesthesia, thus eliminating the risks of intravenous sedation or general anesthesia.

5. Mohs micrographic surgery is cost effective. The procedure is comparable to the cost of electrodessication and curettage, cyrosurgery, and office excision.

History

Developed by Frederic E. Mohs, MD in the 1930’s, the Mohs micrographic surgical procedure has been refined and perfected for more than half a century. Initially, Dr. Mohs removed tumors with a chemo surgical technique. Over the course of a number of days, thin layers of tissue were excised and frozen before being pathologically examined. He developed a unique technique of color-coding excised specimens and creating a mapping process to accurately identify the location of remaining cancerous cells.

As the process evolved, surgeons refined the technique and now excise the tumor, remove layers of tissue and examine the fresh tissue immediately. The normal treatment time has now been reduced to one visit and allows for the immediate reconstruction of the wound. The heart of the procedure – the color coded mapping of the excised specimens and their thorough microscopic examination – remains the definitive part of the Mohs micrographic surgery.

Indications

Mohs micrographic surgery, while used primarily to treat basal and squamous cell carcinoma, can also be used to treat less common tumors, including but not limited to sebaceous carcinoma, dermatofibrosarcoma protuberans, procarcinoma, etc.

Mohs surgery is indicated when:

• The cancer was treated previously and recurred
• Scar tissue exists in the area of the cancer
• The cancer is in a difficult area where it is important to preserve healthy tissue for maximum functional and cosmetic result (ie – eyelids, nose, ear, lips)
• The cancer is large
• The edges of the cancer cannot be clearly defined
• The cancer grows rapidly or uncontrollably
• The cancer has an aggressive growth pattern

Reconstruction

The best method of managing the wound resulting from surgery is determined after the cancer is completely removed. When the final defect is known, management is individualized to achieve the best results and to preserve functional capabilities and maximize aesthetics. The Mohs surgeon is trained extensively in reconstructive procedures and usually will perform the reconstructive procedure necessary to repair the wound on the same day. A small wound may be allowed to heal on its own, or the wound may be closed with stitches, a skin graft or flap. If a defect is large enough to require sedation for the repair, another surgical specialist with unique skills may complete the reconstruction.

Cost Effectiveness

In addition to its high cure rate, Mohs micrographic surgery also has been shown to be cost effective. In a study of costs of various types of skin cancer removal, the Mohs process was found to be comparable to the cost of other procedures, such as electrodessication and curettage, cryosurgery and excision. It was found to be less costly than ambulatory surgery facility excision and radiation therapy.

Efficiency

The ability to perform the procedure in an outpatient office setting, the preservation of the maximum amount of normal skin (leading to smaller scars) and less complicated repairs involving fewer reconstructive procedures all make the Mohs micrographic surgery a most efficient option. Additionally, the high cure rate minimizes the risk of recurrence and eliminates the costs of more comprehensive, serious surgery for recurrent cancers.

Treatment Issues

Common treatment procedures often prove ineffective because they rely on the human eye to determine the extent of the cancer. In an effort to preserve healthy tissue, too little tissue may be removed, resulting in recurrence of the cancer. If the surgeon is overcautious, more healthy tissue than necessary may be removed, causing excessive scarring and disfigurement. Some tumors do not respond as well to common treatments, including greater than two centimeters in diameter, those in difficult locations and those complicated by previous treatment. Removing a recurrent skin cancer is more complicated because scar tissue makes it difficult to differentiate between cancerous and healthy tissue. In these cases Mohs surgery may often be the treatment of choice.

Mohs Micrographic Surgery Procedure

Mohs surgery is a minor surgical procedure normally performed on an outpatient basis in the office. Please be prepared to spend the whole day in our office. Eat a full breakfast and bring a packed lunch or snacks along with some reading material. Our office does provide free WIFI for patient use as well. It is also important to bring a friend or family member along. The surgery is performed in steps or stages. The number of steps or stages required depends upon the size and depth of the cancer.

The actual procedure is as follows:

1. A local anesthetic will be injected into the area of surgery. This is the only part of surgery that will cause any discomfort – the sensation of stinging or burning. The pain of injection can be eased with the use of a topical numbing cream. If you are interested in applying this cream one hour prior to your surgery, please let us know so that we can give you a prescription for it. Please be aware that some patients respond minimally to the topical numbing cream.
2. Once the area is numb, a small layer of tissue will be removed. Unless the cancer is quite small, more surgery is almost always required. Remember, it is always better to initially remove too little and perform a second stage than to remove more normal tissue than necessary.
3. The small amount of bleeding will be stopped with a machine that coagulates the blood vessels, a dressing will be applied, and you will wait in the operating room.
4. This tissue will be brought back to the laboratory, where it will be examined for the presence of skin cancer. The tissue is processed, and microscope slides are prepared and examined.
5. If a microscopic examination reveals remaining tumor, a map is drawn indicating the precise location.
6. Additional anesthetic is injected to reinforce the first injection. In most cases, the initial anesthetic has not worn off and you feel little or no discomfort.
7. The second stage now involves the removal of another layer of tissue – but only where the map indicates residual cancer. The healthy tissue is left alone; only the diseased tissue is excised.
8. The tissue is brought back to the laboratory and the process is repeated until all evident cancer is removed.

The average tumor requires two to four stages for removal. Do not be discouraged if your cancer is not removed in one step. We are tracing the extent of the tumor very carefully and trying hard not to remove any uninvolved normal tissue. This must be done in small layers.

Commonly Asked Questions

“WHAT IS SKIN CANCER?”

Skin Cancer is not one problem but a collection of separate diseases. There are three common forms of skin cancer:

1. Basal Cell Carcinoma
2. Squamous Cell Carcinoma
3. Malignant Melanoma

Basal Cell Carcinoma is not only the most common form of skin cancer, but it is also the most frequently occurring of all cancers of the body. The name is derived from the skin cell that is growing in an uncontrolled fashion – the basal cell. This is the cell type located at the base or bottom of the upper skin layer – the epidermis. Although basal cell carcinoma can damage the skin where it appears, it rarely spreads to other parts of the body unless its size becomes enormous. It does not spread throughout the bloodstream and almost never involves the lymph nodes (glands). One might think of a basal cell carcinoma as a colony of termites. If left untreated, it will destroy any tissue or structure in its path of growth. This is of particular concern when basal cell carcinoma is located near the eye, ear, or nose. One cannot predict how quickly basal cell carcinomas will grow. Although they are usually slow-growing tumors, basal cell carcinomas can grow rapidly and spread. Basal cell carcinomas initially may have the appearance of a small pimple, a non-healing or bleeding sore, a shiny papule, a cyst or a larger growth. Discomfort and itching can occur but are rare. The diagnosis of basal cell carcinoma cannot be confirmed without a biopsy or sample being sent to a pathology laboratory for microscopic examination.

Squamous Cell Carcinoma can be a more serious disease than basal cell carcinoma. The squamous cells are located above the basal layer in the epidermis. This tumor may spread to the nearby glands or lymph nodes or travel through the bloodstream to distant areas of the body. Squamous cell carcinoma usually appears as a rough, scaly plaque or larger growth.

Malignant Melanoma, which often looks like a brown or black patch, or an unusual mole, is potentially the most serious form of skin cancer. However, because microscopically controlled surgery is not often used as the treatment for melanoma, it will not be discussed further.

“WHY DID I GET SKIN CANCER?”

Unfortunately, we do not know most of the factors that cause skin cancer. However, skin cancer does occur more frequently in people with fair complexions (blonde hair, blue eyes), individuals of Celtic descent and those who tend to get damaging ultra-violet radiation of the sun over many years may change normal cells of the skin to cancerous cells. This is why areas of the body exposed constantly to the sun (the face, hands) tend to be more prone to skin cancer than sun-protected areas. However, this is not the entire answer. Dark-skinned individuals who hide from the sun can still develop cancer. Other factors such as heredity and environmental agents may play some role.

“HOW CAN I PROTECT MYSELF FROM FUTURE SKIN CANCER?”

The only factor you can control is exposure to the sun. Proper use of sunscreen with a Sun Protection Factor (SPF) of 30 to 45 or greater is the most important preventative measure. You can also wear broad-rimmed hats or protective clothing if desired. Avoid sun exposure between 10:00 a.m. and 2:00 p.m. and sit in the shade when possible. You do not have to change your lifestyle – only use caution.

“HOW IS SKIN CANCER TREATED?” 

Skin cancer can be treated effectively by a variety of methods, including traditional surgery, desiccation and curettage (scraping and burning), freezing (cryo-surgery), X-ray (radiation therapy) and Mohs, or microscopically controlled, surgery. The treatment of skin cancer must be individualized, taking into consideration such factors as patient’s age, location of the cancer, type of cancer and whether or not the cancer has been treated previously. In some instances, more than one type of therapy may be appropriate. But in most cases, only one or two are necessary for a particular skin cancer.

“WILL THERE BE ANY AFTER EFFECTS OF MY SURGERY?”

Discomfort, if it should occur with this procedure, is usually mild and can be managed with Extra-Strength Tylenol. Do not take aspirin or aspirin-containing products (Excedrin, Anacin, etc.) unless prescribed by your primary care physician for a cardiac or stroke history as these can promote bleeding. A pressure dressing applied to the wound should be left on 1-2 days to minimize swelling and bleeding. Although some minimal bleeding is typical, brisk bleeding after surgery is infrequent. If brisk bleeding occurs, lie down, take some gauze or a dry washcloth and apply firm pressure for twenty minutes (by the clock) on the wound. Do not remove the pressure prior to this. If the bleeding persists, contact the on-call physician at the emergency contact numbers shown on your post-operative instructions.

Other problems that may occur include black and blue marks, swelling, and redness for approximately 2 months and a bumpy suture line for approximately 4 months. Rarely, if the skin cancer involves nerves of the skin, surgical removal can lead to numbness or muscle weakness in the area. Numbness usually resolves in 12-24 months, but may occasionally be permanent.

Remember, every surgical procedure produces scarring of some type. Although every attempt will be made to minimize and hide the scar, the extent of scarring depends on the size and depth of the cancer.

The main goal of Mohs surgery is to remove skin cancer as completely as possible and prevent recurrence. Although the cure rate is not 100%, it offers the highest cure rate of any available procedure. Most patients never require further treatment.

Please remember, this information provides a general guide to skin cancer and Mohs surgery. Please consult your physician if any questions arise.