Mohs micrographic surgery is a surgical treatment for skin cancer that was developed by Dr. Frederick Mohs in the 1930's. It is the most effective technique for removing the most common types of skin cancer. For the two most common types of skin cancer, basal cell carcinoma and squamous cell carcinoma, Mohs has a 98-99% cure rate. The remarkable thing about Mohs is that it manages to be extremely good at removing all of the cancer cells while at the same time leaving behind most of the healthy tissue, so there is a smaller wound. This makes the procedure safer, speeds up the the recovery time, and minimizes scarring.
During Mohs surgery, skin around the cancer site is mapped out and removed in thin layers. Then each layer is examined under a microscope for cancer cells, while the surgery is in progress. If cancer cells are detected, the surgery continues and another layer is removed. If the skin is clear, the surgery can be stopped. This eliminates the guesswork for surgeons. There is no need to estimate the borders or roots of the cancer and no need to remove a margin of healthy tissue to ensure that all of the cancer is removed.
Even though Mohs has a high cure rate, is safer than other treatments, and takes less tissue, not every skin cancer is treated with Mohs. First, Mohs takes quite a bit longer than traditional surgery because each layer of skin must be carefully cut, prepped, and examined. It is also more expensive and may not always be covered by insurance. In addition, for smaller or less aggressive cancers that are easier to treat, the cure rate for non-Mohs treatments is close to that of Mohs; thus, the extra time and cost of Mohs might not be justified. Other kinds of skin cancer, such as melanoma, are hard to see under a microscope. Since melanoma is so dangerous, Mohs has traditionally not been used to treat it, as there is too much risk for missed cancer cells being left behind in the body. However, recent developments in stains (which make cancer cells more visible under a microscope) may change the role of Mohs in melanoma treatment.
Mohs microsurgery has changed the way doctors treat skin cancer in the past 80 years, and it continues to gain in popularity as it increases the effectiveness and safety of skin cancer treatment.