3. What is Mohs Surgery?
What is Mohs Surgery?
Moh’s Micrographic Surgery represents an advanced technique for the treatment of skin cancer and offers the highest potential for cure.
The Mohs’ technique relies on the accuracy of a microscope ensure the removal of a skin cancer down to its roots-- allowing the surgeon to see beyond the visible disease, and to precisely identify and remove the entire tumor, leaving healthy tissue unharmed.
The Mohs’ technique involves removing a thin, saucer-like layer of tissue that is excised just a few millimeters around and underneath the visible skin lesion. This layer is then divided into pieces and inked. A map is then drawn that shows each piece of tissue in relation to the patient. These pieces of tissue are then frozen, mounted in a waxy substance and then sectioned horizontally starting from the underside of the specimen by the Mohs’ histo-technician. The slides are processed within an hour and then examined by the Mohs’ surgeon and pathologist. If tumor roots are seen on the slide extending beyond the section of tissue that was removed then more tumor remains in the patient. Using the map, the “positive margin” on the slide is matched to the precise location on the patient. The process is then repeated and another layer of tissue is removed, but only from the area that showed residual tumor. In this way, surrounding normal tissue is conserved.
Why should I have Mohs surgery?
This selective removal of only diseased tissue allows preservation of much of the surrounding normal tissue, lessening the potential for scarring and disfigurement. Because this systematic microscopic search reveals the roots of the skin cancer, Mohs surgery offers the highest chance or complete removal of the cancer while sparing the normal tissue. Cure rates exceed 99 percent for new cancers and 95 percent for recurrent cancers.
In areas where saving every possible millimeter of skin is essential (nasal tip or eyelids), Mohs is the best choice. In potentially deadly or disfiguring tumors, Mohs often offers the highest cure rate.
In some instances Mohs’ surgery may not be required. Some skin cancers such as malignant melanoma are not typically treated by Mohs’ surgery because these cancerous cells are difficult to visualize on frozen sections utilized in the Mohs’ process. Such cancers require traditional processing of the tissue and as a result, when these tumors are excised, further excision may be necessary in the days or weeks following surgery should the pathologist determine that incomplete excision of the tumor has occurred. In some cases the wound may be left open until complete excision has been confirmed. We refer to this process as “slow Mohs.”
In certain instances, pre-surgical treatment with a topical chemotherapy agent may be indicated in order to minimize the extent of surgery or eliminate the need for Mohs’ surgery at all. Aldara has been recognized as an affective topical cream that can shrink or cure certain types of skin cancer.
Some cancers can be adequately excised without the Mohs technique and still have very high cure rates. In areas where there is plenty of loose skin, such as the neck, saving every millimeter is not needed. This allows a surgeon to remove a tumor with a good margin. The tissue is still processed at a later time to check the margins for complete removal, but the patient does not have to wait for results.
Lastly, some cases surgery may not be possible at all. Because most skin cancers are fairly slow growing and tend not to cause serious harm, surgery may not be appropriate for all patients. Sometimes surgery may be potentially more harmful to the patient than other alternative therapies such as chemotherapy, cryotherapy (freezing) and radiation may be recommended.
What are the benefits of Mohs surgery?
Mohs has the highest cure rate for many types of skin cancer, and has the ability to preserve as much normal tissue as possible.
4. Risks of Mohs Surgery