History of Mohs and the American College of Mohs Surgery (Learning Series pt. III)

In the first two posts of this Mohs Learning Series, I described the reasons why Mohs is gaining popularity and why the need for Mohs is greater than ever. But how did the unique procedure that is Mohs surgery begin? Who was the first person to conduct Mohs surgery? What is the future for Mohs surgeons and patients?

I answer all these questions and more with a simple description of the Mohs history and the development of the American College of Mohs Surgery. I hope that you will find this history as fascinating and relevant in today’s Mohs environment as I do!

Mohs surgery is named after the physician who developed the original technique, Frederic Mohs. (For more information on the Mohs technique, I recommend reading the second post in this Mohs Learning Series, Mohs Surgery: What to Expect.) Frederic Mohs was a practicing physician in Wisconsin the 1930s who discovered a new way to treat skin cancer tumors. When he found a tumor, he painted a zinc chloride paste onto it and sent the patient home with instructions to return the next day. Between these two office visits, the zinc chloride killed the skin tissue. When the patient returned, Dr. Mohs cut off the dead tissue, looked at it under a microscope, and then told the patient either, “I got it” or “I didn’t.” After that the patient went home to heal. If Dr. Mohs felt he didn’t get the tumor out in its entirety, he would start the process all over again.

This was a dramatic change in how tumors were removed. Even in the beginning, this basic technique spared a lot of skin tissue. Dr. Mohs also began to show that he had a pretty high cure rate with his patients.

In the 1950s the Mohs technique advanced to the point where surgeons started to use fresh tissue. They would cut the tissue and then prepare it for analysis. This process still took at least 24 hours, so patients would have to return at least one more day, and sometimes it required several days to completely remove a tumor.

Then, in the 1970s, a landmark paper was written by Drs. Theodore Tromovitch and Samuel Stegman. This paper revealed the development of a technique they called microscopically controlled excision. Microscopically controlled excision is a method of removing tissue from a patient and processing it such that the entire area surrounding the tumor can be visualized under the microscope within an hour. As a result, slides could be prepared and processed while the patient was waiting in the office. Now it took just a little over an hour for each stage instead of overnight. Meanwhile, the cure rates continued to stay high.

During the 1970s and 1980s the invention of cryostats and automatic tissue slide stainers made the process even faster and more reliable. Cryostats are special machines that quickly freeze and cut tissue so that it can be placed on a slide to be examined. Automatic tissue slide stainers place special colors on the slides prepared by the cryostat machine. These colors stain cells in different ways so that tumor cells can be easily distinguished from normal cells. Since this time, the Mohs procedure has been increasingly refined, resulting in even greater speed and efficiency in processing the tissue. Today a typical Mohs patient only has to wait about 30 minutes for each stage.

By the 1980s and 1990s another phenomenon occurred: Mohs surgery had been happening long enough for research to confirm cure rates over extended periods of time. People started to take notice that the Mohs surgery technique was faster and easier and spared skin tissue compared with other methods and had reliable long-term cure rates. When these capabilities are combined with the current epidemic of skin cancer occurring primarily in the face, you can understand why there is a real need for Mohs.

I want to back up in time a little bit to explain the development of the American College of Mohs Surgery. In 1967 Dr. Frederic Mohs founded the American College of Chemosurgery. Remember how Dr. Mohs originally used the chemical zinc chloride? That’s why the college included the name chemosurgery. As the Mohs process evolved over the years, however, the use of zinc chloride was dropped. In 1988 the College changed their name to the American College of Mohs Micrographic Surgery and Cutaneous Oncology. That’s an extremely long name but it accurately described the full spectrum of the work of a well-trained Mohs surgeon. In plain language the name literally means “microscopic mapping surgery and skin cancer.” Finally, in 2007, the college adopted a more user-friendly name: the American College of Mohs Surgery (ACMS).

The ACMS is not an actual physical place. It’s an organization that oversees training, ongoing development, and advancement of Mohs surgery for its members. To become an ACMS member, a physician has to be accepted and then fulfill a rigorous training regimen. (I’ll describe what’s involved to become an ACMS member in my next post.) The ACMS serves a very important role of quality control for surgeons and patients. Its members are well-trained, experienced, and have demonstrated their professional ability while making a lifelong commitment to continuing education and quality control. There is also the American Society of Mohs Surgery, which is not the same as the College. This organization does not have member requirements as stringent as those of the ACMS.

When it comes to physicians who perform Mohs surgery, there are variable levels of training and expertise. The focus of my next and final post in the Mohs Learning Series will be on how to select the right Mohs surgeon for you.

Published on 10/11/2011 | Last updated on 01/05/2017