What is Mohs surgery?
Mohs surgery is a specialized, highly effective technique for removing skin cancers. It 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 cancer tissue so that all roots and extensions of the cancer can be eliminated. Mohs surgery has the highest reported cure rate of all treatments for skin cancer.
While Mohs surgery is an effective option, treating all skin cancers with Mohs surgery is not necessary. Mohs surgery is reserved for skin cancers that grow back after previous treatment, cancers that are at high risk of reoccurring, or cancers that are located in cosmetic areas where preservation of the maximum amount of normal skin is important.
How is Mohs surgery done?
1. The skin is numbed using local anesthetic. The visible cancer is removed with a thin layer of additional tissue. This takes only a few minutes.
2. The specimen is color coded to distinguish top from bottom and left from right. A technician freezes the tissue and removes very thin slices from the entire edge and undersurface. These slices are placed on microscope slides and stained for examination under a microscope. This is the most time consuming part of the procedure, often requiring an hour or more to complete.
3. Dr. Bennion then carefully examines these slides under the microscope. This allows examination of the entire surgical margin of the removed tissue. That is, the entire undersurface and the complete edge of the specimen is examined. All microscopic roots of the cancer can thus be precisely identified and pinpointed.
Why remove skin cancer with Mohs surgery?
Some skin cancers are deceptively large-far bigger 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. Also, skin cancers that recur after previous treatments may send out extensions deep under the scar tissue that has formed. Mohs surgery is specifically designed to remove these cancers by tracking and removing these cancerous "roots."