Mohs Surgery Procedure

We believe the more you know about the excellent care we offer during your Mohs procedure, the more peace-of-mind you’ll have. To help you understand what takes place both in the surgical suite and behind-the-scenes during your procedure, we describe in detail each step we’ll take during your Mohs procedure. If you have any additional questions, please don’t hesitate to ask us!

Step 1 – Prep the Area

Mohs procedure figure A

After confirming the biopsy site with you, the treatment area is cleansed, marked and injected with a local anesthetic. The Mohs surgeon removes visible cancer, along with a thin layer of additional tissue. This will take only a few minutes. Your wound is temporarily bandaged, and you relax while we process and examine the tissue.

Mohs procedure figure B

In our on-site Mohs lab, we cut the tissue sample into sections, then stain and mark it on a detailed diagram called a Mohs map.

We freeze the tissue sample on a cryostat and remove thin slices from the edge and undersurface. Then we stain the sample and examine it under a microscope. This is the most time-consuming portion of the procedure, often requiring an hour or more.

Step 2 – Remove the Cancer at the Root

Mohs procedure figure C

Sometimes, skin cancers have roots or extensions that aren’t visible from the surface. If the skin cancer that was visible during the first stage turns out to be “just the tip of the iceberg,” your Mohs surgeon will use the map to pinpoint any remaining cancer and use it to direct the removal of additional tissue. Additional tissue is removed only where cancer is present.

Step 3 – Repeat the Process (if necessary)

Your skin cancer surgeon will repeat this process through as many stages as necessary to locate and eliminate the cancer. Each time, we will inject additional anesthesia and take another thin margin of skin, precisely where the skin cancer cells are based upon the Mohs map. We repeat the process as many times as needed until there are no remaining skin cancer cells.

Step 4 – Repair

When microscopic examination shows that there is no remaining tumor, the surgical site is ready for repair. Your physician will discuss repair options with you, which can include natural healing or repairing with sutures. Repair options depend on the size and location of your wound; recommendations are made to optimize healing and restore function.

Frequently Asked Questions

Contrary to popular belief it is not an acronym but is the last name of Dr. Frederic Mohs, who developed this procedure.

Mohs is more accurate with a higher cure rate and a smaller scar than any other way to treat skin cancer, since 100% of the margin of the removed tissue is evaluated.

Besides having the highest cure rate, Mohs is far more cost-effective than radiation or excision in an operating room with a plastic surgeon. Also, there is less risk of the cost of retreatment as the cancer is unlikely to recur.

You leave the office knowing the cancer is gone.

Any time the skin is cut there will be a scar. Our surgeons are trained to minimize the size and appearance. The size will depend on the size of the cancer itself.

Most of the time you will have stitches, which will either dissolve or be removed at 1-2 weeks.

Yes you are awake and just have local numbing.

You will be in the office for at least 2 hours, and up to many hours depending on the cancer. Much of that time is comfortably waiting for the tissue to be processed and read.

Yes we encourage you to bring a friend or family member if you like, and especially if the surgery is near the eye or other areas which would make driving home difficult.

Wear comfortable clothes. Please do not wear makeup if the surgery will be on the face.

Yes please eat your usual meal prior to your appointment.

Yes take all of your prescribed medications prior to surgery unless directed by the surgeon.

Avoid over the counter blood thinners like Omega-3 (fish oil), chondroitin, dan shen, feverfew, garlic tablets, ginger tablets, ginkgo, and ginseng. Also avoid NSAIDs including ibuprofen (Advil, Motrin) and Naprosyn (Aleve) and any other prescription anti-inflammatories, unless your surgeon prescribes them. You will be able to take these NSAIDs after the surgery, and we actually encourage these for postoperative pain control. You may take Tylenol (acetaminophen) unless otherwise instructed not to do so.

It is important to minimize heavy activity or swimming for 1-2 weeks after the surgery.

As with any surgery, there is always a risk of bleeding, infection, slow healing, numbness. Mohs surgery has the lowest chance of recurrence of the cancer–just 1%.

Mohs surgery is almost always covered by insurance. Please contact your insurance company or our billing office with questions.

Images courtesy of the American Society of Mohs Surgery, of which Dr. Prosise and Dr. Chen are Fellows. Additional information regarding the procedure can be found on their website.