The Mohs Micrographic Surgery procedure relies on a specific sequence of surgery and pathological investigation:
STEP 1: The roots of a skin cancer may extend beyond the visible portion of the tumor. If these roots are not removed, the cancer will recur.
STEP 2: The visible portion of the tumor is surgically removed.
STEP 3: A layer of skin is then removed and divided into sections. The Mohs surgeon then color codes each of these sections with dyes and makes reference marks on the skin to show the source of these sections. A map of the surgical site is then drawn.
STEP 4: The undersurface and edge of each section are then microscopically examined for evidence of remaining cancer.
STEP 5: If cancer cells are found under the microscope, the surgeon marks their location onto the “map” and returns to the patient to remove another layer of skin – but only precisely where the cancer cells remain.
STEP 6: The removal process stops when there is no longer any evidence of cancer remaining in the surgical site. Because Mohs surgery removes only tissue containing cancer, it ensures that the healthy tissue is kept intact.