Mohs micrographic surgery is a type of cutaneous oncology (cancer) surgery that is most effective in removing primarily basal cell carcinomas, squamous cell carcinomas and melanoma-in-situ. Mohs surgery is a tissue sparing procedure that offers cure rates of skin cancer superior to that of other treatment options. It has evolved as the most reliable and cost-effective treatment modality, offering maximal preservation of normal tissue and therefore the lowest functional and cosmetic morbidity.
The procedure was developed by Frederick Mohs in the 1930’s and was appropriately named chemosurgery by its inventor because of the chemical interaction between zinc chloride and human tissue. In the 1980’s the American College of Chemosurgery changed its name to the American College of Mohs Micrographic Surgery.
Mohs’ micrographic surgery (MMS) technique is best described through illustration and photography. This method identifies close to 100% of the peripheral and deep margins as opposed to a standard excision that looks at 3-5% of the margin. The most important concept to grasp is this: Mohs surgery is a specialized way of processing the tissue to look at close to 100% of tumor margin; it is the way we process and look at tissue that defines Mohs surgery.
The technique involves not only a fellowship trained Mohs surgeon, but also a well-equipped Mohs lab complete with a cryostat and tissue staining abilities.
Areas of cancer found with the microscopic examination are located on maps, drawn both on paper and the tissue itself. This way a re-excision is performed only where residual tumor is located and spares normal tissue. The excised tissue is frozen and sectioned horizontally, then read along with the graphical mapping to assure correct orientation.
Please watch the informative patient video at www.mohscollege.org. The Mohs college website is a good resource for questions about the procedure. Answers to questions regarding specific skin cancers can be found at skincarephysicians.com and www.aad.org.