Mohs surgery was developed by Frederic E. Mohs during the 1930s when
he was a medical student at the University of Wisconsin. Dr. Mohs used
a chemical fixative paste (zinc chloride), which was applied topically
to cutaneous tumors. He was then able to excise layers of tissue without
the use of local anesthesia in a relatively bloodless field. Frozen
horizontal sections were performed of the entire undersurface of the
specimen as well as of all the peripheral margins. If residual tumor
was found, the steps were repeated. This procedure became known as Mohs
chemosurgery (1). The drawback of this technique was that only one layer
of skin could be removed per day, and therefore the technique could
take several days to remove a malignancy. Also, because of the caustic
nature of the paste, all wounds had to heal by secondary intention.
The cure rates for the technique, however, were extremely high, approaching
98 percent for primary basal cell and squamous cell carcinomas and 96
percent for recurrent tumors.
In the 1950s, Dr. Mohs ceased using zinc chloride paste for eyelid tumors
because of its irritation of eye tissue. This was the first use of the
"fresh tissue" technique as it is known today. In the 1970s, Dr. Theodore
Tromovitch showed that all basal cell and squamous cell carcinomas could
be removed without the use of zinc chloride paste by substituting local
anesthesia, while maintaining the high cure rates. This fresh tissue
technique allowed extensive tumors to be removed in a single day and
reconstruction to begin immediately following tumor extirpation. Chemosurgery
has been replaced by the term Mohs micrographic surgery, which is now
used in order to more accurately describe the technique.
