Mohs Micrographic Surgery
Mohs micrographic surgery is a specialized, highly effective technique for the removal of skin cancer. The procedure was developed in the 1930s by Dr. Frederic Mohs at the University of Wisconsin and is now practiced throughout the world.
It’s advantage over other skin cancer treatments in that it permits the immediate and complete microscopic examination of the removed cancerous tissue, so that all “roots” and extensions of the cancer can be eliminated. Because of the methodical manner in which tissue is removed and examined, Mohs surgery has been recognized as the skin cancer treatment with the highest reported cure rate.
It is important to note that Mohs surgery is not appropriate for the treatment of all skin cancers. Mohs micrographic surgery typically is reserved for those skin cancers that have recurred following previous treatment or for cancers that are at high risk for recurrence. Mohs surgery also is indicated for cancers located in areas such as the nose, ears, eyelids, lips, hairline, hands, feet, and genitals, in which maximal preservation of healthy tissue is critical for cosmetic or functional purposes.
Some skin cancers can be deceptively large,far more extensive under the skin than they appear to be from the surface. These cancers may have “roots” in the skin, or along blood vessels, nerves, or cartilage. Skin cancers that have recurred following previous treatment may send out extensions deep under the scar tissue that has formed at the site. Mohs surgery is specifically designed to remove these cancers by tracking and removing these cancerous “roots.” For this reason, prior to Mohs surgery it is impossible to predict precisely how much skin will have to be removed. The final surgical defect could be only slightly larger than the initial skin cancer, but occasionally the removal of the deep “roots” of a skin cancer results in a sizeable defect. The patient should bear in mind that Mohs surgery removes only the cancerous tissue, while the normal tissue is spared.
Typically, Mohs surgery is performed as an outpatient procedure in the office. Although the patient is awake during the entire procedure, discomfort is usually minimal and no greater than it would be for more routine skin cancer surgeries.The area to be treated is cleansed, marked, and injected with a local anesthetic. The Mohs surgeon removes the visible cancer, along with a thin layer of additional tissue (Stage I). This procedure takes only a few minutes, and the patient waits while tissue is being processed and examined. The removed tissue specimen is cut into sections, stained, and marked on a detailed diagram. The tissue is then frozen on a cryostat, and the technician removes very thin slices from the entire edge and undersurface. These slices are then placed on slides and stained for examination under the microscope. (This is the most time-consuming portion of the procedure, often requiring one hour or more to complete.)
The Mohs surgeon carefully examines the entire undersurface and complete edge of the specimen, and all microscopic “roots” of the cancer are precisely identified and pinpointed on the Mohs map. Upon microscopic examination, if residual cancer is found, the Mohs surgeon utilizes the Mohs map to direct the removal of additional tissue (Stage II). Note that additional tissue is removed only where cancer is present.This process is repeated as many times as necessary to locate any remaining cancerous areas within the tissue specimen (Stage III, Stage IV, etc.)
When microscopic examination reveals that there is no remaining tumor, your Mohs surgeon will discuss the following options with you:
1) Allowing the wound to heal naturally, without the necessity of additional surgery (which may produce the best cosmetic result).
2) Simple or complex wound repair performed by the Mohs surgeon.
3) Referral to the original referring physician for wound repair.
4) Referral to a plastic surgeon for wound repair.
If your wound requires daily care at home, you will be given detailed instructions following your surgery.
If you are taking prescription medications, continue to take these unless otherwise directed by a physician. However, you should inform your Mohs surgeon if you are taking blood thinning medications such as coumadin, Plavix, aspirin, aspirin substitutes (such as Advil, Motrin, Nafton, Naprosyn, etc.), vitamin E, gingko, garlic, ginseng, ginger, ephedra, fish oil or other nutritional supplements. These medications and supplements can sometimes cause an increased chance of bleeding during and after surgery.
It is important that you obtain a good night’s rest and eat normally on the day of your surgery. For your comfort, it is recommended that you wear casual, layered clothing. You may also wish to bring a light snack and a book or magazine to help occupy your waiting time. Also, it may be advisable to arrange for someone to drive you home following surgery, if needed.
Most Mohs cases can be completed in three or fewer stages, requiring less than four hours. However, it is not possible to predict how extensive a cancer will be, as the extent of a skin cancer’s “roots” cannot be determined in advance. Therefore, it is advisable to reserve the entire day for this surgical procedure, in case the removal of additional layers is required.
Most patients do not complain of significant pain. If there is some discomfort, normally only Tylenol is required for relief. However, stronger pain medications are available and will be prescribed when needed. You may experience some bruising and swelling around the wound, especially if surgery is performed near the eye area.
As with all forms of surgery, a scar will remain after the skin cancer is removed and the surgical area has completely healed. Mohs micrographic surgery, however, will leave one of the smallest possible surgical defects and resultant scars. Often, wounds allowed to heal on their own result in scars that are barely noticeable. Even following extensive surgery, results are frequently quite acceptable. In addition, scars do have the ability, through the body’s own natural healing properties, to remodel and improve in appearance for a six to twelve month period. There are also many other techniques available to the patient for enhancement of the surgical area following skin cancer surgery.
Patients should understand that there is not an absolute guarantee that any given procedure will be totally free of complications or adverse reactions. Mohs surgery is no exception. During surgery, tiny nerve endings are cut, which may produce a temporary or permanent numbness in and around the surgical area. If a large tumor is removed or extensive surgery is required, occasionally a nerve to muscles may be cut, resulting in temporary or permanent weakness in a portion of the face or other regions. This is, however, an unusual complication. The surgical area may remain sensitive for several weeks or months after surgery, especially if large amounts of tissue were removed. Rarely, some patients may experience intermittent itching or shooting pain in the surgical area as healing occurs. This will generally gradually subside and resolve.