The MOHS Process
Mohs Surgery is a complex procedure combining surgical excision with immediate microscopic examination of the entire tissue specimen margin by frozen tissue processing techniques right in the office while you wait. In addition to your physician, who serves as the Mohs surgeon and pathologist, two to three histotechnologists are employed to process, cut, and stain the tissue specimen for proper histological study.
To begin Dr. Conti examines the spot where you had your biopsy and may mark it with a pen for reference. He positions you for the best access, which may mean sitting up or lying down. A surgical drape is placed over the area. If your skin cancer is on your face, that may mean you can’t see what’s happening, but the staff and surgeon talk you through it. A local anesthesia, which numbs the area completely, is injected into area to be treated. You stay awake throughout the procedure.
Using a scalpel, Dr. Conti removes a thin layer of visible cancerous tissue. Some skin cancers may be “the tip of the iceberg,” meaning they have roots or extensions that are not visible from the surface. The lab analysis, which comes next, will determine that. Your wound is bandaged temporarily and you can relax while the lab work begins.
Dr. Conti then cuts the tissue into sections; color codes them with dyes and draws a map of the surgical site. In the lab, one of our highly trained technicians freezes the divided tissue and then cuts very thin horizontal slices like a layer cake. The slices are placed on microscope slides, stained and covered. This meticulous process takes time.
Using a microscope, Dr Conti examines all the edges and underside of the tissue on the slides and, if any cancer cells remain, marks their location on the map. The staff then lets you know whether you need another layer of tissue removed.
Back in the procedure room, they may inject more anesthesia if needed and proceeds to remove another layer of skin, precisely where the cancer cells remain, based on the map. Then, while you wait, the lab work begins again. This entire process is repeated, as many times as needed until there are no more cancer cells.
Once the site is clear of all cancer cells, the wound may be left open to heal by second intention (on its own) or Dr. Conti may close it the same or next day. This depends on its size and location. In many cases, he will coordinate the repair of your wound with another specialist such as our board certified facial and body plastic and reconstructive surgeons.
If more than one or two rounds are needed, the entire process can take up to several hours, so be prepared for that. It is worth it, though, because this precise technique has the highest cure rate of any treatment method and can save the greatest amount of healthy tissue, leaving the smallest scar possible. Carefully follow your doctor’s instructions for wound care, scar care and follow-up to achieve the best outcome.
