What is MOHS Surgery?
Mohs surgery is a method to immediately check the margins of a skin cancer taken from a patient to see if the cancer has been cured. It involves cutting the specimen into four quarters and examining the edges by the person who removed the lesion from the patient. Dr. Frederic Mohs, a general surgeon, treated his first patient with the technique on June 23, 1936. Today, it is primarily performed by dermatologists (who are not surgeons). Plastic Surgeons, General Surgeons, Ophthalmologists, and Otolaryngologists (Ear, Nose, and Throat Surgeons) are surgeons who remove skin cancers and generally do not do Mohs surgery.
Dermatologists state that Mohs surgery is necessary in cosmetically sensitive or functionally critical areas around the eyes, nose, lips, scalp, ears, fingers, toes, or genitals, when the cancer is large, aggressive, or growing rapidly, when the cancer is recurrent, or when the cancer has ill-defined edges. They state that Mohs surgery gives the greatest cure rate with the least amount of sacrifice of normal tissue.
The Mohs method involves systematically removing thin layers of tissue which are then examined under a microscope by the dermatologist for malignant cells. When all areas of tissue are tumor-free, the excisional aspect of the surgery is complete.
There is no argument that surgical removal of skin cancer is the “Gold Standard” for skin cancer treatment. So why is it that only dermatologists (non-surgeons) use this technique?
There are many concerns regarding the utilization and overutilization of Mohs surgery:
- The vast majority of skin cancer surgery does not require immediate verification of negative margins. A simple football shaped removal and closure is most often all that is necessary to cure a skin cancer and is the least expensive, best cosmetically appealing, procedure.
- If an immediate verification of cure is necessary it can be done with a frozen section. A frozen section differs from Mohs surgery in two ways. First, the tissue is bread-loafed for examination rather than cut into quarters as in Mohs. Second, an independent specialist in microscopic examination of tissue, a pathologist, examines the specimen rather than the dermatologist doing both duties. Pathologists could quarter the tissue in the manner of Mohs surgery but they do not feel it is useful to do so.
- The Mohs surgery method removes the tissue from the patient in thin slices, often necessitating multiple layers of tissue to be removed. Each layer is billed and reimbursed separately for the pathologic examination. This is not the case when Plastic Surgeons remove skin cancers since Plastic Surgeons generally do not perform the pathologic examination and are only paid one time for the surgery.
- Many dermatologists may not know how to repair the defect they have created, requiring the patient to seek help from a Plastic Surgeon. This increases cost and inconvenience.
- Dermatologists say that Mohs surgery is tissue sparing (in other words less skin is removed to cure the cancer). This has not been shown to be true.
- Since dermatologists often do not repair difficult defects that they have created, they may not remove the cancer in a way that is most advantageous to the repair. Plastic Surgeons are trained to cure the skin cancer and repair the defect in the most cosmetically pleasing way.
Do not be misled. Mohs surgery is generally done only by non-surgeon dermatologists, it is not new, it is not usually needed, and, by using the frozen section technique, an essentially equivalent technique can be done by Plastic Surgeons on the rare occasions when it is necessary.