Mohs uses both surgery and microscopy to precisely identify and remove cancer cells during the surgical process. That's why it offers much higher cure rates than conventional surgical procedures.
Not all cancer cells are apparent to the eye. Many "invisible" cells may form roots that extend beyond the visible cancer. If not removed, these cells can lead to recurrence. Mohs surgery helps ensure that all affected cells are removed.
Mohs relies on the accuracy of a microscope to trace and remove skin cancer down to its roots. Once there's no sign of disease, the process stops. This means only diseased tissue is removed and cosmetic issues are minimized.