Mohs’ surgery is widely recommended for the treatment of certain basal cell and squamous cell carcinomas, as well as other less frequently diagnosed skin malignancies. Tumor characteristics such as size, location, margin definition, the risk of recurrence, and anatomic location are factors to be considered in the selection of Mohs’ surgery as the optimal treatment choice.
During the procedure, the Mohs’ surgeon removes the known tumor, including a small area of surrounding normal tissue. A map is drawn, showing the orientation of the excised tissue relative to the location of the patient. While the patient waits, the Mohs’ technician processes the tissue specimen using a horizontal sectioning method and prepares microscope slides for examination by the dermatologist. The Mohs’ surgeon also acts as the pathologist in interpreting the deep and peripheral margins of the excised tumor, using the map as a reference. If additional areas of tumor are seen, the process is repeated until no further tumor involvement is noted in any of the margins. Because of the methodical manner in which the tissue is removed and examined in Mohs surgery, the cure rate is as high as 99 percent for certain skin cancers.