Mohs micrographic surgery is the most effective and state-of-the-art procedure for skin cancer today, which offers the highest potential for recovery – even if the skin cancer has been previously treated by another method and recurred.
What is Mohs Surgery?
Mohs is a specialized micrographic surgical technique used to remove cancerous lesions in the skin. Allowing physicians to remove skin cancer more effectively, while causing less damage to surrounding healthy tissue than any other method, Mohs is particularly ideal for the removal of large tumors, such as those with irregular edges, and skin cancer that appears on the face or near delicate parts of the body.
Why does my skin cancer need Mohs Surgery?
Mohs Micrographic Surgery is primarily used to treat basal and squamous cell carcinomas, but can be used to treat less common tumors including melanoma.
Mohs Surgery is appropriate when:
- The cancer is in an area where it is important to preserve healthy tissue for maximum functional and cosmetic result, such as eyelids, nose, ears, lips, fingers, toes, genitals;
- The cancer was treated previously and recurred;
- Scar tissue exists in the area of the cancer;
- The cancer is large;
- The edges of the cancer cannot be clearly defined;
- The cancer is growing rapidly or uncontrollably.
How is Mohs Performed?
The first step in the Mohs micrographic surgery process is the removal of the visible portion of the tumor. This is accomplished through surgical excision or curettage (scraping). Once this step is complete, a thin sample of tissue is taken from the area of which the tumor was removed then carefully examined with a powerful microscope to screen for the presence of any additional cancerous tissue. If such tissue is found, its precise location is determined and another small section of tissue is removed from this area. This sample is examined under the microscope as well, and the process is continued until it is determined that no additional cancerous tissue remains. By using this systematic method to seek out the roots of a tumor, Mohs surgeons have a 97 to 99 percent chance of successfully removing the entire cancer, leaving the surrounding tissue largely unharmed. Mohs surgery has been especially helpful for removing cancerous tumors when other forms of treatment have been unsuccessful.
The final stage of the Mohs surgical procedure is the closing of the wound left by the excision. The specific method used to complete this step will depend on the size, shape, and location of the incision. Small, shallow openings may be dressed and left to heal naturally, while larger wounds may need to be closed with stitches or repaired with a skin graft. The decision as to which of these methods will be most effective is generally made once the cancer has been removed and the extent of the excision is known.
Non-Melanoma Skin Cancer
Skin cancer is the most common form of cancer seen in the United States. About 1 million people are diagnosed every year. The most common form of skin cancer is basal cell carcinoma followed by squamous cell carcinoma and many other less common types. Skin cancers are most common in fair-skinned older patients however, with increasing UV exposure and ozone layer depletion; patients are being diagnosed at a much younger age.
Basal cell carcinoma (BCC) is slow growing but can be locally invasive if not removed early. These lesions usually appear as pearly, red bumps on sun-exposed areas. BCC is asymptomatic but bleeding with minimal trauma may be the first symptom. Previous therapy with x-rays (for facial acne) or arsenic exposure (even 30-40 years prior) increase the risk for BCC as well.
Squamous cell carcinoma (SCC) often arises from pre-cancerous lesions called actinic keratoses. These lesions usually appear as crusted or scaly patches with a red, inflamed base on sun-exposed parts of the skin. SCC is also seen more commonly in organ transplant patients and in previously traumatized skin. SCC can spread more easily to other parts of the body and should be treated as soon as possible after diagnosis.
Both BCC and SCC are diagnosed through skin biopsy and treated with Mohs micrographic surgery (when lesions appear on the head and neck) or surgical excision (when lesions are small and on the body). Mohs surgery allows the surgeon to take a sampling of skin and view it under the microscope to ensure all of the tumor has been removed. Newer topical treatments or photodynamic therapy can sometimes also be used in very superficial skin cancers.
Melanoma Skin Cancer
Melanoma is the most serious type of skin cancer. It occurs when pigment cells in the skin called melanocytes are exposed to ultraviolet (UV) radiation. If the skin receives too much ultraviolet light, the melanocytes may begin to grow abnormally and become cancerous. Other risk factors include fair skin, family history of first-degree relatives with melanoma, history of one or more severe sunburns, a weak immune system and exposure to certain carcinogens. If melanoma has a chance to grow deep in the skin, it has a much higher chance of spreading to other parts of the body than other types of cancer. The first sign of melanoma is often a change in the size, shape, or color of a mole, but melanoma can also appear on the body as a new mole. Abnormal moles can appear anywhere on the skin. That’s why it is important to always examine your skin to check for new moles or changes in moles. In men, melanoma most often shows up on the back, head or neck. In women, melanoma often develops on the lower legs. Moles that change in color or in texture, take on an uneven shape, get larger, or become bigger than a pencil eraser should be evaluated immediately.
If a melanoma is diagnosed early, treatment consists of wide excision and/or Mohs surgery depending on the type of melanoma. Melanomas diagnosed later are harder to treat and require more invasive diagnostic techniques including sentinel lymph node biopsy. Beyond excision, treatments for deeper melanomas can include radiation therapy, chemotherapy, and immune therapies.
Why choose Torrey Pines Dermatology?
Dr. Kristen Richards, our Founder and CEO, is one of very few Fellowship-trained Mohs micrographic surgeons here in San Diego. The American College of Mohs Micrographic Surgery and Cutaneous Oncology (www.mohscollege.org) is the official organization responsible for training Mohs surgeons and maintaining a high standard of care in the specialty of Mohs surgery. To become a member of this organization and to be known as a Mohs surgeon, a special one to two-year fellowship, following a dermatology residency, is required. Only a limited number of dermatologists are trained each year to be Mohs surgeons, in order to maintain the highest level of competence in the specialty.
If your doctor has referred you to Torrey Pines Dermatology to have Mohs micrographic surgery at our La Jolla practice, you will be scheduled for a preoperative consultation. This visit allows Dr. Kristen Richards to examine your skin cancer, obtain your medical history, and determine whether the technique of Mohs micrographic surgery is the most appropriate treatment for you. It also gives you the opportunity to meet Dr. Kristen Richards and her staff and learn about the procedure.