Mohs' Micrographic Surgery
Mohs' Micrographic surgery is a specific technique used in removing some skin cancers. It was developed initially by a general surgeon in Wisconsin (Dr. Frederic Mohs) almost 80 years ago, and modified by some dermatologists in the 1970's. The technique involves removing the skin tumor, and having the tissue frozen and placed onto several glass slides for examination by the surgeon while the patient waits.
The key is to examine only the bottom and the edges of the tumor that was removed, utilizing a "map" of the tissue as a guide. The tissue is stained with various color dyes so the surgeon can determine the exact location of any portion of the tumor that may have not been removed, if indeed any portion of the tumor is inadvertently left behind. The surgeon can then go back to the patient and remove more tissue at that location, and then re-examine this second piece in an identical manner. This process is repeated until no more tumor is seen in the processed frozen sections. At that point, the tumor is declared "clear".
Mohs' Surgery is an excellent adjunct to our treatment of skin cancer. The question, of course, is when to utilize this technique. Many skin cancers can simply be removed using simple visualization of what appears to the experienced skin cancer surgeon to be the edge of these tumors. This simpler technique, called "excision", which is usually followed by suturing closed the wound, can cure a large majority of skin cancers.
- Specialized skin cancer surgical technique
- Developed by Dr. Frederic Mohs in 1940s
- Tumor margins are checked while patient waits
There are definite circumstances when the Mohs' technique would be preferable, and here is where the judgement of the surgeon is indicated. Mohs' surgery is indicated for situations where the tumor has been removed previously and has recurred at the same site; or if the edges of the tumor are too difficult to ascertain by simple visual inspection; or if the tumor has features under the microscope that make it more likely to recur if the Mohs' technique is not utilized; or if an extremely precise removal of tissue such as the Mohs' technique offers significant advantages such as on portions of the nose.
In our practice, the majority of skin cancers are removed by excision and only rarely recur. But at those times when Mohs' surgery is indicated, it is an extremely helpful and gratifying technique.
- Recurrent skin tumors
- Skin cancers with edges that are difficult to visualize
- Tumors with aggressive features under the microscope
- Cosmetically difficult tumor location (e.g., nose, eyelid, lip, ear)
- Majority of skin cancers can be removed with conventional surgery with no recurrence