Mohs surgery is commonly performed to treat non-melanoma skin cancers (basal cell carcinoma, squamous cell carcinoma, and many others). Additionally, our laboratory utilizes special immunohistochemical stains to treat thin melanomas as well.

Mohs surgery is an outpatient procedure that is performed under local anesthesia; therefore, the risks associated with prolonged general anesthesia are avoided. Before the surgery begins, a small needle is used to place the numbing medicine in the area surrounding the skin cancer. The surgeon then removes the obvious skin cancer that can be seen with the unaided eye. Next, a very thin saucer-shaped layer of normal appearing skin is removed taking special care to map the tissue. The tissue is then processed by the laboratory located in our office and a detailed map is constructed – a process that takes approximately 60-120 minutes. Microscopic slides are prepared and then examined by the surgeon to determine if the cancer is persistent.

If microscopic examination reveals remaining tumor at the margin, then further tumor excision is required. After returning to the surgical suite, additional anesthetic is injected to reinforce the initial injection. In most cases, the area is still numb and little to no discomfort is felt. Another layer of tissue is then removed – only where the map indicated residual cancer. This tissue is again brought to the laboratory, and the process is repeated until all cancer is removed. Once all the cancer has been removed, we will then discuss the options to reconstruct the resulting defect or open wound. This usually requires stitches.

Because the number of stages (or layers) involved with each case is unpredictable, it is impossible to know how long the surgery will take. For this reason, it is important for patients to plan on spending the entire day with us, although most patients are only in the office for half of a day. Do not be discouraged if the cancer is not removed in one step since tracing of the cancerous roots of the tumor is conducted in small layers. Bring a good book and whatever else will help keep you comfortable while you are with us.