Mohs Micrographic Surgery
Mohs Micrographic Surgery is a specialized tissue-sparing surgical technique used to remove skin cancers with the highest possible cure rate. Mohs Surgery is named after its inventor, Dr. Frederic Mohs, who was a surgeon in the 1930's. The technique has been modified and refined over time. As it involves the surgeon performing the roles of both surgeon and pathologist only board-certified dermatologists can perform Mohs Surgery.
While any board-certified dermatologist can perform Mohs Surgery, only fellowship-trained Mohs surgeons have received rigorous and specialized training in the technique and subsequent reconstructive surgery. While there is no official board-certification in Mohs Surgery, it is important that your Mohs surgeon was officially trained in a fellowship accredited by the American College of Mohs Surgery (ACMS) and/or the Accreditation Council of Graduate Medical Education (ACGME). These are the only recognized training bodies for Mohs Surgery, and as of 2013 the ACMS will transition all future training accreditation to the ACGME. For more information, please visit mohscollege.org.
Mohs Micrographic Surgery Procedure
Mohs Surgery is performed as an outpatient procedure in our surgery suite at Carolina Mountain Dermatology. Upon arrival you will be brought into a room and the cancer will be marked and confirmed by both you and your surgeon. The area will then be numbed with local anesthesia. Your surgeon will remove the visible tumor along with a thin margin of tissue around it. A bandage is then placed on the surgical defect and you will wait for approximately 45-60 minutes in a comfortable waiting room while the tissue is processed.
- Once ready, your surgeon will examine nearly 100% of all peripheral and deep margins of your tissue with a microscope to determine if there is still any cancer present. Any areas containing residual cancer cells are marked on a map. You are then brought back into the surgery suite where you are given more local anesthesia and another thin layer of tissue is removed by the surgeon in the positive area(s) only. This process is repeated until all margins are clear.
- After the cancer is cleared, your surgeon will work with you to decide upon the best way to repair the surgical defect. Mohs surgeons are highly trained in reconstructive surgery and in most cases your surgeon will repair your defect the same day as your surgery. In rare instances, your surgeon may refer you to other specialists for repair if necessary.
- This process can be time-consuming, as each layer requires at least 30-60 minutes of time to process and examine. Therefore, anticipate spending the entire day at the office for your procedure. Most cases, however, do not last more than a few hours. You may feel free to bring food and beverages with you to the procedure as you are free to eat and drink as you normally would during the surgery.
- A modified Mohs technique is used to treat melanoma as the tissue must be specially processed. Only one layer is taken each day for melanoma and sent off to an outside lab. You then come back the next day for either another layer or closure depending on the lab results. Each visit lasts 45-60 minutes.
Advantages of Mohs Micrographic Surgery
- Mohs Surgery is performed under local anesthesia, and as such, carries none of the risks associated with general anesthesia.
- Mohs Surgery provides the highest possible cure rate for many skin cancers - approaching 99% for some non-melanoma cancers.
- Mohs surgery preserves as much healthy skin as possible during removal of the cancer, which is important in cosmetically sensitive areas.
Risks of Mohs Micrographic Surgery
The Mohs technique itself does not carry any unique risks, however surgery does carry inherent risks unto itself.
- Any surgery carries a risk of pain, bleeding, infection, scarring, possible adverse change in cosmetic appearance, possible adverse change in anatomic functionality, possible adverse change in sensation, as well as a risk of nerve damage, both motor and sensory, which may be permanent. The repair of any surgical defect also carries the same risks.
- Local anesthesia also carries a risk of pain, bleeding, and the possibility of an allergic reaction which in rare instances could cause anaphylaxis and even death.
- Leaving a cancer in place also carries its own set of risks, including the possibility of cosmetic and functional impairment, as well as in some cases, death if left untreated. These risks are carefully weighed against the risks of surgery, and the decision to perform surgery is only made if the benefits of surgery far outweigh the risks.
What types of cancers are treated?
- Basal cell carcinoma (BCC) is a cancer of the bottom layer of cells in the epidermis. It generally will grow locally by spreading out wider and deeper. BCC does not usually metastasize (spread) to other areas of the body, but if left untreated it can invade into fat, muscle, cartilage and bone.
- Squamous cell carcinoma (SCC) is a cancer of epidermal cells called keratinocytes. SCC also spreads locally, but also can metastasize if left untreated and ultimately could cause death.
- Melanoma is a cancer of pigment-producing cells, and is not related to BCC or SCC. While deadly in later stages, melanoma is very treatable early on with surgery.
- As Mohs is a specialized form of surgery it is not used for the removal of every skin cancer. Your dermatologist and surgeon will determine if you are a candidate for Mohs surgery.
- If your tumor is no longer visible after biopsy, it should still be removed if recommended by your dermatologist. While the surface of the tumor was removed, more cancer cells may remain hidden under the skin. These cells can continue to grow and spread. Only Mohs surgery uses a microscope to search for these remaining cells during your surgery.