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Developed by a meticulous, pioneering general surgeon and refined by a host of forward-thinking dermatologists, Mohs micrographic surgery (MMS) represents the standard of care today for treatment of many cutaneous tumors. With cure rates unparalleled by standard destructive and excisional surgeries and the innate ability to preserve healthy surrounding tissue, MMS should be considered for large, aggressive, or recurrent carcinomas as well as those in functionally or cosmetically sensitive areas. In utilizing the serial staged excisional process as illustrated subsequently, the Mohs surgeon is able to immediately repair ensuing wounds as necessary. Due to the safety and cost-effective nature of the procedure, MMS appropriately represents the gold standard for treatment of many cutaneous tumors.


As a sophomore medical student at the University of Wisconsin, Frederic Mohs, while experimenting with the injection of zinc chloride and other chemicals into rat tumors, noted excellent preservation of the microscopic features of the treated tissue. After shaving the tumor nodules horizontally with respect to the skin surface, he made the observation that zinc chloride acted as an in situ fixative. The in situ fixation along with the concept of horizontal sectioning initiated a series of experiments that has eventually led to modern MMS. In 1936, the first patients were treated with chemosurgery, and in 1941, Dr. Mohs reported success using microscopic surgery on 440 patients.1 Initially termed “chemosurgery” to indicate that the tissue was chemically treated and surgically excised, early chemosurgery procedures were initiated by the application of a paste composed primarily of zinc chloride applied to malignant tissue. After a period of 4 to 24 hours, saucerized surgical excision ensued followed by microscopic examination of the horizontal sections. Accordingly, Mohs confirmed tumor removal or precisely identified remaining tumor, repeating the staged excision as necessary.

Traditional medicine proved slow to adopt Mohs’ chemosurgery technique. The early days of the procedure were met with great skepticism and hostility. With meticulous records and eventually adequate patient data revealing extremely high cure rates, chemosurgery began to gain acceptance. Despite being trained as a general surgeon, Dr. Mohs recognized that dermatologists represented the most interested group of physicians in his technique. Thus, following the creation of American College of Chemosurgery in 1967, the college’s first meeting was held that year, and consisted of 23 attendees of the American Academy of Dermatology Annual Meeting.2

Chemical fixation used in the initial chemosurgery posed several challenges, namely the time consuming nature of the standard 24 hour fixation, the pain associated with chemical fixation, and the limited reconstruction options following the final excision of tissue. These were all overcome upon the development of the fresh tissue technique using horizontal frozen sections without zinc chloride fixation. Although Dr. Mohs first used the technique in 1953, a presentation by Dr. Theodore Tromovitch at the American College of Chemosurgery Annual Meeting in 1970 reporting his success using ...

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