Mohs Micrographic Surgery, an advanced treatment procedure for skin cancer, offers the highest potential for recovery—even if the skin cancer has been previously treated.
This procedure is state-of-the-art treatment in which the physician serves as a surgeon, pathologist, and reconstructive surgeon. It relies on the accuracy of a microscope to trace and ensure removal of skin cancer down to its roots. This procedure allows dermatologists trained in Mohs surgery to see beyond the visible disease and to precisely identify and remove the entire tumor, leaving healthy tissues unharmed. This procedure is most often used in treating two of the most common forms of skin cancer: basal cell carcinoma and squamous cell carcinoma.
The success rate for Mohs Micrographic Surgery is the highest of all treatments for skin cancer – up to 99 percent – and is effective even when other forms of treatment have failed. This procedure, the most exact and precise method of tumor removal, minimizes the chance of re-growth and lessens the potential for scarring or disfigurement.
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 indicated when:
- The cancer was treated previously and recurred
- Scar tissue exists in the area of the cancer
- The cancer is in an area where it is important to preserve healthy tissue for maximum functional and cosmetic results, such as eyelids, nose, ears, and lips
- The cancer is large
- The edges of the cancer cannot be clearly defined
- The cancer grows rapidly or uncontrollably
The Mohs process includes a specific sequence of surgery and pathological investigation. Mohs surgeons examine the removed tissue for evidence of extended cancer roots. Once the visible tumor is removed, Mohs surgeons trace the paths of the tumor using two key tools:
- Map of the surgical site
Once the obvious tumor is removed, the Mohs surgeon:
- Removes an additional, thin layer of tissue from the tumor site
- Creates a map of the removed tissue to be used as a guide to the precise location of any remaining cancer cells
- Microscopically examines the removed tissue thoroughly to check for evidence of remaining cancer cells
If any of the sections contain cancer cells, the Mohs surgeon:
- Returns to the specific area of the tumor site as indicated by the map
- Removes another thin layer of tissue only from the specific area within each section where cancer cells were detected
- Microscopically examines the newly removed tissue for additional cancer cells
If microscopic analysis still shows evidence of disease, the process continues layer-by-layer until the cancer is completely gone. This selective removal of only diseased tissue allows preservation of much of the surrounding normal tissue. Because this systematic microscopic search reveals the roots of the skin cancer, Mohs Surgery offers the highest chance for complete removal of the cancer while sparing the normal tissue.
The best method of managing the wound resulting from surgery is determined after the cancer is completely removed. When the final defect is known, management is individualized to achieve the best results and to preserve functional capabilities and maximize aesthetics. The Mohs surgeon is also trained in the reconstructive procedures necessary to repair the wound. A small wound may be allowed to heal on its own, or the wound may be closed with stitches, a skin graft or a flap. If a tumor is larger than initially anticipated, another surgical specialist with unique skills may complete the reconstruction.
The Mohs Surgeon
The highly-trained surgeons that perform Mohs micrographic surgery are specialists in both dermatology and pathology. With their extensive knowledge of the skin and unique pathological skills, they are able to remove only diseased tissue, preserving healthy tissue and minimizing the cosmetic impact of the surgery. Only physicians who have also completed a residency in dermatology are qualified for Mohs Micrographic Surgical training.
The American College of Mohs Micrographic Surgery and Cutaneous Oncology currently recognizes more than sixty training centers where qualified applicants receive comprehensive training in Mohs Micrographic Surgery. The minimum training period is one year during which the dermatologist acquires extensive experience in all aspects of Mohs Surgery, pathology, and training in reconstructive surgery.