LAUSR

In 1910, Frederic Edward Mohs, MD, was born in Burlington, Wisconsin. Although initially he trained to become a radio engineer, Dr Mohs transitioned to medicine in college. While he attended medical school at the University of Wisconsin, he worked with Dr Michael Guyer, a cancer researcher, and cultivated an interest in preparing frozen tissue for histological study. Here, he made the vital discovery that zinc chloride paste could “fix” skin tissue for microscopic examination, setting the foundation for the Mohs micrographic surgery (MMS) technique. Dr Mohs began performing the procedure, initially dubbed “chemosurgery,” in 1936 on patients with skin cancer. During the procedure, he first applied dichloroacetic acid to the involved area to remove keratin from the epidermal layer. He then applied zinc chloride paste for fixation, which could take hours to days depending on how well the paste penetrated the sample. After adequate fixation, Dr Mohs excised a saucer-shaped layer of fixed tissue, followed by cross-sectioning the specimens into pieces that were 1 cm × 1 cm × 2 mm in size and mapping out slices to their corresponding anatomical locations. DrMohsmicroscopicallyexaminedeachsectionforthepresenceofcancer. Sections negative for cancer required no further workup, but sections positive for cancer led to continued surgery in the sections’ corresponding locations. Zinc chloride paste was reapplied to that region, and the entire procedure was repeated until the cancer was removed. Mohs micrographic surgery was a groundbreaking technique because it allowed the maximum sparing of healthy tissue while removing all cancerous cells. Despite its effectiveness, Dr Mohs’ technique initially faced great skepticism. The early to mid-1900s was rampant with cancer quackery, as numerous pills and potions claimed to “cure cancer.” Harry Hoxsey, one alternative medical proponent, used zinc chloride in pseudocancer treatments. As a result, zinc chloride, also present in Dr Mohs’ paste, was largely rejected by the medical community. Furthermore, surgeons then believed that cutting into a tumor caused it to spread, leading to further disbelief over the MMS technique. The technique gradually gained acceptance when Dr Theodore Tromovitch, a dermatologist who trained with Dr Mohs, transitioned Mohs’ fixed-tissue technique to a freshtissue one without the use of caustic zinc chloride. This, alongside Dr Mohs’ high cure rate, helped MMS gain full acceptance. Ultimately, Dr Mohs’ belief in the scientific rigor of his technique allowed him to persist through the strong skepticism. Countless patients have since been treated with MMS for basal and squamous cell carcinomas, including President Ronald Reagan in 1985. Dr Mohs died on July 2, 2002, but his legacy lives on through the American College of Mohs Surgery, which has over 900 members.