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Mohs Surgery

Anheuser Busch Institute

1755 S. Grand Blvd.
St. Louis, MO 63104
Ph: (314) 256-3420

Des Peres Medical Arts Pavilion II
2315 Dougherty Ferry Road, Suite 200 A
St. Louis, MO 63122
Ph: (314) 977-9721


    Facts about Mohs Surgery:
  • Mohs surgery was developed in the 1940’s by Dr. Frederick Mohs, a general surgeon from the University of Wisconsin, as a method to remove skin cancers.
  • Mohs surgery is a specialized technique for removing various types of skin cancer.
  • Mohs surgery is also known as microscopically controlled surgery. A microscope is not used during surgery, but is used to examine skin tissue immediately after it has been surgically removed.
  • Mohs surgery provides the opportunity for the evaluation of all tissues around the surgical margins as compared to a “sampling” of the margins, which occurs with routine evaluation of excised tumor specimens.

Mohs surgery procedure:

Mohs surgery differs little from other types of cutaneous (skin) surgery. A local anesthetic is used to numb the surgical area. The surgical procedure begins by excising around the skin cancer with a scalpel. Only the area that appears to be abnormal is first excised. After the excision is completed, the area is bandaged. The surgery itself takes only a few minutes, however tissue processing may take up to 60 minutes.

Our certified histotechnician prepares slides of the tissue and our Mohs surgeons will review the removed tissue in our frozen section laboratory. The tissue section is examined under a microscope to see if there is any skin cancer on the outer edges. If we find cancer, we know that some skin cancer remains at the excision site. If cancer remains, we ensure that the area is still anesthetized, then repeat the Mohs surgery procedure. Only the cancerous tissue is removed which preserves the most amount of healthy skin. This procedure is repeated until the entire area has been cleared of skin cancer. In most cases the area is then immediately reconstructed. Each Mohs excision is referred to as a “stage.” On the average, it takes 2 or 3 stages to remove all of the skin cancer. One may require only 1 or 2 stages, or many stages, depending on the cancer. Unfortunately, we are unable to predict by visual inspection how many stages will be necessary.

Our goal is to remove all of the skin cancer, while at the same time preserving the maximum amount of surrounding healthy tissue. Mohs surgery offers a high cure rate and minimizes the removal of healthy tissue. As a result, not only is all of the skin cancer removed, but also the best overall cosmetic results are possible. It is important to note, however, that not all surgical areas are small. Some skin cancer can be quite extensive. The size of the surgical defect from Mohs surgery is determined by the size and nature of the skin cancer. Although Mohs surgery has the highest cure rate for several skin cancers, it is not 100% successful. The risk of recurrence is only 1-5% for most cancers, depending on location and type of cancer, with recurrent skin cancers being more likely to recur. Some cancers and certain situations may have a higher risk of recurrence. In all cases, close follow-up after surgery by the referring physician is crucial to monitor any possible return of skin cancer. In addition, once there is a diagnosis of skin cancer, there is a higher risk for developing a second skin cancer. Regular check-ups with a dermatologist are important so that any recurrence or new skin cancer can be treated early.

Multidisciplinary Evaluations of Melanoma:

Saint Louis University is proud to have a Multidisciplinary Melanoma Conference that meets regularly to discuss new cases of melanoma. The Multidisciplinary Melanoma group consists of physicians from Dermatology, Dermatopathology, Surgical Oncology, Medical Oncology, Pathology, Radiation Oncology, Otolaryngology and Plastic Surgery. We meet monthly to discuss management of patients, including the review of pathology, staging, and treatment options. The Multidisciplinary Conference is an important forum that allows physicians from multiple specialties to collaborate, ensuring that melanoma patients receive the most comprehensive care.