What is Mohs Surgery?   Mohs surgery can be described as the surgical removal of skin cancer and other appropriately-indicated malignancies followed by microscopic examination of graphically-oriented, oblique tangential histologic sections of the entire surgical margin of excised tissue, to ensure the complete removal of the malignant tissue.   In other words, the Mohs surgeon removes the first level of cancerous tissue, draws a corresponding diagram or "map" to ensure proper orientation on the patient, and the Mohs technician efficiently sections and stains the tissue to prepare a microscope slide. The Mohs surgeon then "reads" the slide to determine which margins still contain cancer cells.