Mohs Micrographic Surgery
What is Mohs surgery?
Mohs micrographic surgery is a surgical treatment that was developed by Dr. Frederick Mohs in the 1930s. It is the most effective surgical treatment for removing basal cell carcinoma and squamous cell carcinoma.
Specifically, it is a surgical procedure in which skin cancer is removed layer by layer. Each layer of tissue is examined under a microscope until the margins are clear. Clear margins means that the edges of the tissue removed are free of cancer cells when visualized under a microscope. The use of the microscope during the procedure provides an extremely precise method for removing cancerous tissue; at the same time, sparing the greatest amount of healthy tissue and preventing the need for additional surgery. Mohs surgery may result in smaller surgical defects and less noticeable scarring, as compared to other surgical methods to remove skin cancer. The Mohs procedure is recommended for skin cancer removal in areas where maximum preservation of healthy tissue is desirable for cosmetic and functional purposes (i.e. face, scalp, etc).
How is it performed?
The Mohs procedure is usually done as an outpatient, meaning that you don’t have to be admitted to the hospital to have this procedure done. The office where you have the procedure done will be equipped with a surgical suite and a laboratory so that the tissue can be checked for cancer cells on-site. The procedure will most likely be completed in one day. Most tumors require 1 to 3 stages for complete removal of cancer cells.
The steps to the Mohs procedure are as follows:
- The surgeon will examine the lesion and plan how much tissue to remove. The goal is to remove the roots of the cancer because if they are not removed the cancer will recur.
- A local anesthetic is either applied or injected. A local anesthetic numbs only the surgical area. Notify your provider if this is not managing your pain.
- The surgeon will remove the visible portion of the tumor with surgical tools.
- Next, a deeper layer of skin is removed and cut into sections. Each section will be color-coded with dye that will coincide with a reference mark left on the skin to indicate where each section of the skin was removed from. A surgical site map will be drawn to track where each portion of the tissue came from.
- A specialist will look at each section of the skin under a microscope to look for any remaining cancer cells.
- If cancer cells are found on any sections of tissue under the microscope the surgeon will mark the location on the map and will remove another layer of tissue from the corresponding area of the patient’s skin.
- The removal process will continue until no cancer cells are seen from any removed sections of skin.
- The surgeon will decide what type of reconstruction will be needed to heal the site. Some incisions will heal on their own, known as secondary-intention healing. A larger wound may be closed with stitches. An even larger wound may require a skin graft from another part of the body or a skin flap, which uses skin adjacent to the Moh’s site to cover the wound. If the site does not appear to be able to be healed by any of these techniques the patient may need to be seen by a reconstructive surgeon.
- After the procedure is complete you will be given time to rest and you will be given instructions to follow at home.
It is normal for some patients to experience discomfort, bleeding, redness, and inflammation. They are temporary and should be easily managed.
What will my care be like after the procedure?
Your provider will give you instructions as to how to care for your incision site once you go home. Each case is different, but you should receive instructions including:
- How and when to change bandages and clean the surgical site.
- Prescriptions and/or information about medications and topical ointments to use following the procedure.
- Timeline including when you can resume activities, such as exercising.
- Schedule for follow-up appointments to monitor healing and remove any stitches.
- Instructions for treating the scar to promote healing and fading.
Your provider will schedule follow-up appointments to monitor your incision area and provide any follow-up care such as wound care or removal of sutures. Your provider will also monitor you for any recurrence of your cancer.
American College of Mohs Surgery. 2017. Found at: http://www.mohscollege.org/about-mohs-surgery. Retrieved 28 Dec 2015
Skin Cancer Foundation. Mohs Surgery. Found at: http://www.skincancer.org/skin-cancer-information/mohs-surgery/mohs-overview.