Mohs Surgery is a highly specialized technique designed for the treatment of skin cancer. The procedure was developed in the 1930s and has been refined and perfected over the years. Mohs surgery differs from other treatments of skin cancer in that it permits the instant examination of the cancerous tissues so that no roots of the cancer remain in the patient.
Mohs surgery relies on careful mapping and preparation of the removed tissue and uses the precision and accuracy of the microscope to map out the roots of the tumor, which would otherwise not be visible. Skin cancer tumors can be deceptively large, and Mohs surgery allows the surgeon to be sure that the tumor is completely removed.
As previously mentioned, Mohs surgery has the key benefit of allowing the doctor to remove the cancerous tissue completely so that it does not recur. These cancers can have microscopic extensions in the skin as well as along nerves, cartilage and blood vessels. If a patient was previously treated with another procedure, the skin cancer may reappear with deep extensions under the scar tissue. Mohs surgery was designed to remove these cancers by tracing and removing these cancerous roots.
Other benefits of Mohs surgery include:
- the highest remission rate for skin cancer
- the lowest chance of regrowth
- minimizing the potential for scarring and disfigurement
- the most exact and precise method for removal
Because the damage is so minimal, Mohs surgery is often ideal for treating skin cancers in cosmetically sensitive areas, such as around the nose, lips, and scalp.
The area to be treated is cleansed, marked, and injected with a local anesthetic. The Mohs surgeon removes the visible cancer, along with a thin layer of additional tissue (Stage I). This procedure takes only a few minutes, and the patient waits while tissue is being processed and examined.
Tissue is frozen on a cryostat, and technician removes very thin slices from the entire edge and undersurface. These slices are then placed on slides and stained for examination under the microscope. (This is the most time-consuming portion of the procedure, often requiring one hour or more to complete.)
The Mohs surgeon carefully examines the entire undersurface and complete edge of the specimen, and all microscopic “roots” of the cancer are precisely identified and pinpointed on the Mohs map. Upon microscopic examination, if residual cancer is found, the Mohs surgeon utilizes the Mohs map to direct the removal of additional tissue (Stage II). Note that additional tissue is removed only where cancer is present.