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.
Mohs surgery differs from 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.
Due to 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.
Overview of Mohs Surgery
In Mohs surgery, the dermatologist performs the dual role of skin cancer surgeon and pathologist. The Mohs procedure involves the surgical removal of the visible portion of the skin cancer, along with a layer of the surrounding skin.
This tissue is then divided into sections and color-coded by the Mohs surgeon, while corresponding reference marks are made on the patient to indicate the source from which each section was taken.
The surgeon then draws a map of the surgical site, and the tissue is processed to create microscope slides for examination and analysis by the physician. He or she then examines the undersides and edges of each section microscopically for evidence of remaining cancer cells.
If cancer is still present, the involved areas are carefully marked on the map and the patient is prepared to undergo removal of another layer of tissue. It is important to note that any additional tissue is removed only from the area(s) in which cancer cells are still evident on microscopic examination. This process is repeated until no further evidence of cancer remains at the surgical site.
Indications for Using Mohs Surgery
Mohs surgery is indicated for skin cancers in anatomic areas in which preservation of the maximum amount of surrounding healthy tissue is critical for functional and/or cosmetic purposes, such as the eyelids, nose, ears, fingers, toes, and genitalia.
It is also used to excise previously treated skin cancers that have recurred over time, skin cancers containing scar tissue, large skin cancers, skin cancers with borders that are not clearly defined, and skin cancers that demonstrate certain unusual growth patterns.
Skin cancers with aggressive subtypes, such as sclerosing or infiltrating basal cell carcinomas, also may require the use of Mohs surgery. The dermatologist will consider a number of factors in determining whether Mohs surgery is indicated for a particular skin cancer.
Effectiveness of Mohs Surgery
Clinical studies have demonstrated that Mohs surgery provides five-year cure rates approaching 99% for new cancers and 95% for recurrent cancers.
Important advantages of the Mohs procedure:
- It allows the greatest amount of surrounding healthy tissue to remain intact, potentially reducing the size of the final surgical defect and resulting scar.
- The methodical manner in which all lateral and deep tissue margins are examined enables the surgeon to detect and remove any “roots” of the skin cancer that may be present, which greatly reduces the likelihood of recurrence.
Mohs Training and Experience
Residency training in dermatology provides the basic skill set from which the Mohs technique is derived: skin cancer pathology, cutaneous histopathology, dermatologic surgery, and the repair of complex surgical defects.
The Mohs surgeon continues to enhance these skills in residency and, once in practice, through repeated observation and performance of the Mohs technique. Challenging medical education courses with an emphasis on Mohs surgery, observational preceptorship training with other highly experienced Mohs surgeons, and formal Mohs fellowships all are available options for post-residency Mohs training.
Each experience encourages further advancement and refinement of the dermatologist’s surgical skills and enables him or her to treat progressively more complex Mohs cases.
Team Approach to Skin Cancer Treatment
In an effort to provide the best possible medical care, Mohs surgeons sometimes treat patients in partnership with other specialists such as oculoplastic surgeons, ENT (ear, nose and throat) specialists, oral surgeons, plastic surgeons, and radiation oncologists. If indicated for your condition, your Mohs surgeon will discuss these options in detail with you.
Special Qualifications of the Mohs Surgeon
Water’s Edge Dermatology physicians performing Mohs surgery have specialized skills in dermatology, dermatologic surgery, dermatopathology, and Mohs surgery. Basic and advanced training in Mohs surgery is available through selected residency programs, specialized fellowships, observational preceptorships, and intensive training courses.
In addition, your Water’s Edge Dermatology Mohs surgeon has the required surgical and laboratory facilities, and is supported by a well-trained Mohs nursing and histotechnological staff.
Your Water’s Edge Dermatology Mohs surgeon can provide you with detailed information regarding his or her training in the above disciplines, as well as all applicable professional affiliations.
Advantages of the Mohs Surgical Procedure
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, or roots, 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, however, that Mohs surgery removes only the cancerous tissue, while the normal tissue is spared.
The Mohs Surgical Procedure
Typically, Mohs surgery is performed in your Water’s Edge Dermatology 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
Insurance Coverage for Mohs Surgery
Most insurance policies cover the costs of Mohs surgery and the reconstruction of the resultant surgical area.
Patient Preparation for 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®, Naprosyn®, etc.), vitamin E, gingko, garlic, ginseng, ginger, ephedra, or other nutritional supplements. These medications and supplements can sometimes cause an increased chance of bleeding 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.
What to Expect After Surgery
Most patients do not complain of significant pain. If there is some discomfort, normally only Tylenol (acetaminophen) 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.
Options for Post-Surgical Reconstruction
After the skin cancer has been removed, your Water’s Edge Dermatology surgeon will discuss the following options with you:
- Allowing the wound to heal naturally, without the necessity of additional surgery (which may produce the best cosmetic result)
- Simple or complex wound repair performed by the Mohs surgeon
- Referral to the original referring physician for wound repair
- Referral to another surgeon for wound repair
Wound Healing, Scarring, and Scar Revision
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 6-to-12-month period. There are also many other techniques available to the patient for enhancement of the surgical area following skin cancer surgery.
Depressed or indented scars may be elevated using a facial filler such as Radiesse® or Sculptra®. Likewise, a raised or roughened scar may be smoothed using laser resurfacing or chemical peeling techniques. Skin flaps and grafts also may require a subsequent touch-up procedure to further improve their appearance.
Mohs Surgery FAQs
Is Mohs surgery the best treatment option for all skin cancers?
Is Mohs surgery more expensive than other types of skin cancer treatment?
Will Mohs surgery be covered by my insurance plan?
Will Mohs surgery be covered by my insurance plan?
Will Mohs surgery leave a scar?
You should keep in mind, however, that the tissue-sparing nature of the Mohs technique may result in a smaller, less noticeable scar than other skin cancer removal methods. The Mohs surgeon also may be able incorporate suture lines into the patient’s natural skin lines and folds.
Most scars improve in appearance naturally over time, and future scar revision techniques may be employed if necessary.
My skin cancer is in a very noticeable facial area and I am concerned about my appearance following Mohs surgery. Should I have the skin cancer removal performed by a plastic surgeon?
How can I locate a board-certified Mohs surgeon?
American Society for Mohs Surgery (ASMS) Fellow and Affiliate members must be board certified in dermatology by the American Board of Dermatology or the American Osteopathic Board of Dermatology.
The surgical, histopathologic interpretation and reconstruction components of Mohs surgery are routinely taught to dermatologists in their residency training. In addition, dermatologists are examined in these areas by their respective boards.
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