Mohs surgery was developed by Dr. Frederic E. Mohs in the early 1930s as a special technique for the removal of skin cancer, and it is now practiced throughout the world at specialized centers. It permits the immediate and complete microscopic examination of the removed cancer tissue, so that all roots and extensions of the cancer can be eliminated. Mohs surgery has the highest reported cure rate of all treatments for skin cancer and minimizes the amount of tissue removed, resulting in smaller scars. Some skin cancers look deceptively small and are far bigger under the skin than they appear on the surface. These cancers may have roots in the skin along the blood vessels, cartilage, or nerves. Mohs surgery is specifically designed to track and remove these roots.

How Is Mohs Surgery Performed?

There Are Three Steps Involved In Mohs Surgery:

  • The skin is numbed using a local anesthetic, and the visible cancer is removed along with a thin layer of additional tissue. After this procedure, the patient may return to the waiting room. A detailed diagram (a Mohs map) of the removed specimen is drawn.
  • The specimen is color-coded to distinguish the top from the bottom and the left from the right. A technician freezes the tissue and removes very thin slices from the entire edge and undersurface. These slices are placed on a microscope slide and stained for examination under the microscope. This is the most time-consuming part of the procedure, often requiring an hour or more to complete.
  • Your surgeon will then carefully examine the slides under the microscope. This allows examination of the entire undersurface and the complete edges of the removed tissue specimen. Any microscopic roots of the cancer are precisely identified and pinpointed on the Mohs map.

If additional cancer is found on the slides, our surgeon will use the Mohs map to remove additional tissue only where cancer is present. This allows the Mohs technique to leave the smallest possible surgical scar, because no guesswork is involved in deciding where to remove additional tissue. Only tissue around the roots and extensions of the cancer is removed.

How Long Does Mohs Surgery Take?

Most cases can be completed in three or fewer stages. However, we cannot predict how extensive your cancer will be, as the size of the skin cancer roots cannot be estimated in advance. We ask that you reserve the entire day for your surgery, in case multiple stages are required.

For more information about Mohs surgery, please feel free to visit the website of the American College of Mohs Surgery (ACMS) at