Mohs Micrographic Surgery
The following information is provided as a service to our patients and their families who are considering Mohs micrographic surgery. Mohs micrographic surgery is named after the originator of the procedure, Dr. Frederic Mohs. If you have any questions or need additional information, please feel free to contact our staff.
Skin Cancer
What is skin cancer?
Skin cancer is a common tumor which occurs with increased frequency as we age and we accumulate more sun exposure. There are several common types of skin cancer: Basal Cell Carcinoma, Squamous Cell Carcinoma and Melanoma. Melanoma is a very different kind of skin cancer and will not be considered in detail in this brochure. Basal Cell Carcinoma is by far the most common of the three. Squamous Cell Carcinoma is the next most common.
How is skin cancer treated?
A variety of methods may be used to treat skin cancer. These include electrodesiccation and curettage (electrical burning combined with scraping), excisional surgery, x-ray treatments, cryosurgery (freezing) and Mohs surgery. For each tumor and patient an appropriate treatment method is selected. Factors that enter into this decision include patient preference, tumor size, tumor location and tumor growth pattern.
Occasionally, the selected method may be unsuccessful and the tumor grows back. This is because the skin cancer had irregular extensions that escaped detection and removal.
Is skin cancer dangerous?
The most common types of skin cancer are Basal Cell Carcinoma and Squamous Cell Carcinoma. Both types enlarge locally from the point of origin and usually do not spread (metastasize) to distant parts of the body. If not completely removed, both types may invade and destroy structures in their path. Compared to other forms of cancer, these types of skin cancer (Basal Cell and Squamous Cell) are generally recognized in the early stages and are more easily cured.
Malignant Melanoma may be life threatening if not treated early. It usually appears as a brownish-black spot or bump on the skin that enlarges and sometimes bleeds. Occasionally, melanoma originates in moles that have been present for many years. Melanoma does have a tendency to metastasize.
What are the causes of skin cancer?
The cause of skin cancer, like other forms of cancer, is not completely known. Prolonged exposure to sunlight, the majority of which occurs before the age of twenty, is the most important factor associated with the development of skin cancers on the face and arms. Fair-skinned people develop skin cancers more frequently than dark-skinned people do. Cancers of the skin are more common in sunny climates. In addition to fair complexions, other possible factors contributing to the development of skin cancer include family genetics, radiation, trauma and exposure to certain chemicals.
How does skin cancer begin?
Skin cancer begins in the uppermost layer of the skin, spreading along the surface and downward, forming extensions of cells similar to roots. Usually the top portion of a skin cancer is either scaly or fragile; this part often bleeds and forms a sore or crust. However, the outside and underlying edges of a skin cancer may not have this appearance; these outer extensions often cannot be directly seen. Therefore, what is apparent to the naked eye on the surface of the skin may be “the tip of the iceberg.”
Mohs Micrographic Surgery
What is Mohs Micrographic Surgery?
Mohs Micrographic Surgery is a highly specialized procedure for the removal of skin cancer. It is especially useful in tumors that are difficult to remove because of body site or tumor growth pattern (including tumors that have recurred).
There are three steps to Mohs Micrographic Surgery:
- The Mohs surgeon identifies the visible portion of the skin cancer; this visible portion is removed by excision (cutting) or curettage (scraping).
- The Mohs surgeon then maps out and removes a thin layer of normal-appearing tissue at the edges of the previous visible cancer.
- The Mohs surgeon examines the excised tissue with a microscope to see if there is any cancer left.
Before the tissue is examined with the microscope, it is marked with colored dyes and processed with special stains. In doing so, we are able to document and pinpoint the exact location of the tissue that was removed and any remaining cancer. By examining the outside edges (including the depth) of the tissue, the Mohs surgeon is able to trace out and exactly locate any remaining areas of cancer. If cancer remains, steps 2 and 3 of the procedure are repeated but only in the areas that still have cancer.
Revised - 4/19/05
