Approaching Skin Cancers: Mohs vs. Excision

You had a biopsy that showed skin cancer – now what? While there are many ways to treat skin cancers, two of the most common methods are ‘excisions’ and ‘Mohs surgery.’ Both carefully cut out the skin cancer and have excellent cure rates, but each has unique applications.

Mohs surgery, named after Dr. Frederic Mohs, who developed the procedure, is a process where the skin cancer is removed with a small area around it. After this layer is removed, the tissue is processed immediately in the lab while the patient is in the clinic. The dermatologic surgeon then looks at all the borders surrounding the skin cancer to see if any roots are going in a particular direction. If there are still roots, the dermatologic surgeon goes back in and selectively removes them. Once the skin cancer is gone, the area where the skin cancer grew gets stitched up. The Mohs procedure allows for high cure rates while taking as little tissue as possible, but it does add some time in the office. This process is typically used in cosmetically sensitive areas, such as the face, and with aggressive tumors.

Excisions achieve the same goal – removing skin cancer – but are used in areas where it is safe to take a slightly wider safety margin. For example, if the growth is on the back, adding a few millimeters in width to remove the cancer does not have any functional or aesthetic impact. In these cases, we can cut out the cancer with margins we know will remove the tumor and stitch it up immediately. We always send the tissue to the lab to confirm it’s all out, but you go home right after the removal.

So, which should you do? Every patient is unique, and deciding how to treat your cancer is a discussion between you and your provider. We take the location, type of cancer, overall health, and ultimately your preferences into consideration when advising in this process.