What is MOHS Surgery
What is MOHS Surgery?
There are five standard methods for treatment of skin cancers. The two nonsurgical treatments are cryotherapy (deep freezing) and radiation therapy. The three surgical methods include simple excision, physical destruction (curettage with electrodesiccation) and Mohs micrographic surgery. Newer methods of investigation include photodynamic therapy and immunochemotherapy.
In the past, Mohs Micrographic Surgery was sometimes called chemosurgery or Mohs chemosurgery. Originally, chemicals were applied to the skin during the surgery and hence, the name chemosurgery. Chemicals are now rarely used, but the name chemosurgery continues to be associated with the procedure.
Mohs Micrographic Surgery allows for the selective removal of the skin cancer with the preservation of as much of the surrounding normal tissue as possible. Because of this complete systematic microscopic search for the “roots” of the skin cancer, Mohs Micrographic Surgery offers the highest chance of complete removal of the cancer while sparing the normal tissue. The cure rate for new skin cancers exceeds 97%. As a result, Mohs Micrographic Surgery is very useful for large tumors, tumors with indistinct borders, tumors near vital functional or cosmetic structures, and tumors for which other forms of therapy have failed. No surgeon or technique can guarantee 100% chance of cure.
History of Mohs
Mohs Micrographic Surgery is named after its founder and originator, Frederic E. Mohs, MD (1910-2002). As a medical student from 1929 to 1934, Dr. Mohs conducted cancer research projects while working for his mentor and zoology professor, Michael Guyer. Dr. Guyer was familiar with the preparation of frozen tissue for producing microscopic slides and had authored a book explaining how to harvest and process tissue for microscopic examination. These microscopic techniques were later used by Dr. Mohs to map out cancer around nerves, blood vessels, muscle and bone. The cancers he examined were removed by shave or saucerizing excision, a technique that removed cancer as a thin disc of tissue so that the tumor and the inflammatory white-cell infiltrate surrounding the cancer could be examined with the microscope.
In 1953, Dr. Mohs accidentally performed a fresh tissue excision on a lower eyelid and was surprised with the excellent results. After this, he began to use fresh tissue excision for all his eyelid margin cases, as well as for small discrete cancers in other locations. After Dr. Theodore Tromovitch's paper detailing microscopically controlled excision with fresh unfixed tissue was published, Dr. Mohs and most other chemosurgeons of the day began to use the fresh tissue technique almost exclusively. This change eventually brought about a name change from Chemosurgery to Mohs (Micrographic) Surgery.
In the 1970s, specific machines called cryostats were developed to assist the process of freezing live tissue for examination under a microscope. Automatic tissue staining machines were added in the 1980s to assist clinics with the growing number of patients and tissue samples. Throughout all the technical improvements in devices and refinements of technique, the focal point–the color-coded mapping of excised specimens and their thorough microscopic examination–remains the defining characteristic of Mohs micrographic surgery to this day.
~ American College of Mohs Surgery
