Dermatology

Frequently Asked Questions About Mohs Surgery

What should I expect on the day of my consultation?

The Mohs surgery team will complete a consultation during which we will ask that you complete a brief form about your past medical history. The consultation is to ensure you understand why you have been referred for the procedure, what options you have for treatment and what to expect the day of your surgery. The consultation also helps the doctors determine if you are medically prepared for the procedure. After this consultation, you will be scheduled for surgery.

What should I expect the day of my surgery?

You should eat your regular breakfast and take all of your medications as usual on the day of surgery unless specifically told otherwise. A nurse completes a preoperative evaluation. The doctors will clean the surgical field with an antiseptic and inject you with local numbing medicine. You will not be put to sleep; however, please have someone drive you home.

Once the surgical area is numb, the skin cancer will be cut out, sent to the lab and made into microscope slides. The process may take 30 to 45 minutes. If there is some cancer left based on the microscopic exam, the process of removing tissue is repeated until the entire tumor has been completely removed based on microscopic examination.

While most patients have their skin cancers removed in two or three "rounds" of surgery, it is impossible to know exactly how many rounds it will take for your skin cancer. Expect to be here for half of a day. Similarly, it is impossible to know exactly how large your wound will be until the surgery is completed.

Once the skin cancer has been removed, the wound is repaired. The repair may be performed by suturing the wound directly, rearranging skin from adjacent areas (flap), grafting skin removed from another site, or allowing it to heal by itself without suturing. The wound size and location determine the type of repair performed.

Common risks of the procedure include pain, bleeding, infection, scarring, numbness and nerve damage, and the risk of recurrence. Ice and medication is the first step for pain control after surgery. The risks of bleeding and infection are approximately one to two percent, but can be minimized with careful post-operative care. While Mohs surgery guarantees the highest cure rates, no technique offers a 100 percent chance of a cure. There is a small chance, at least one to two percent, depending on tumor type and location, that the skin cancer will recur.

Anytime the skin is cut, a scar will develop. All steps are taken to minimize the cosmetic and functional significance of any scars. It is important to remember that complete healing of the scar takes place over 6 to 12 months. The surgery site may feel swollen, "lumpy," and there may be redness for the first few months after surgery. This is part of the normal healing process.

What are the benefits of Mohs surgery?

Mohs surgery offers the highest cure rate for nonmelanoma skin cancers, usually greater than 95 percent. This is due to the more careful evaluation of the tissues. Additionally, less healthy tissue is removed during Mohs surgery than during a routine excision. This offers an added advantage for removing tissue in delicate areas of the nose, eyelid, ears and lips. In addition, Mohs surgery is offered in an office setting with local anesthesia for added safety and cost effectiveness.

If Mohs surgery has the best cure rate for nonmelanoma skin cancer, why aren't all skin cancers removed with Mohs surgery?

There are multiple treatments available for skin cancers, including electrodessication and curettage (burning and scraping), laser, excision, radiation, interferon and topical 5-fluorouracil. Your skin specialist can assist you in the selection of the optimum treatment. Each situation is different, but with proper selection, cure rates of 90 to 93 percent with the above techniques are expected. The key is proper selection.

Who are candidates for Mohs surgery?

Mohs surgery should be considered in basal cell and squamous cell carcinoma at risk for recurrence. These factors are well known and are based on past history, type of basal cell carcinoma and location. Recurrent tumors, tumors in the "T" or "H" zone (midface and ears), large tumors (greater than 2 cm) are all candidates for Mohs surgery. In addition, certain basal cell carcinomas such as morpheaform, infiltrating, micronodal, adenoid and multifocal tumors are more likely to recur and thus are candidates for Mohs surgery. Squamous cell carcinomas can also be addressed well. With Mohs surgery some rare tumors such as dermatofibrosarcoma protuberans, microcystic adnexal carcinoma are successfully treated with Mohs surgery. We also use a modified Mohs surgery on early melanoma in selected cases.

As you can see, the decision for Mohs surgery as opposed to alternative therapies is complex. Your skin specialist can assist you in the evaluation of your lesion, including biopsy, and help you decide if Mohs is appropriate for you.

Learn more about skin cancer and Mohs surgery