Mohs Surgery

Mohs micrographic surgery is a highly specialized state-of-the-art treatment for skin cancer in which the physician serves as the surgeon, pathologist and reconstructive surgeon. It relies on the precision and accuracy of a microscope, rather than the human eye, to trace out and ensure complete removal of skin cancer – down to its roots. Mohs surgery offers the highest cure rate of all the treatments available for skin cancer – up to 99% for primary basal and squamous cell carcinomas. It is the most exact and precise means of removal, offering the lowest chance of recurrence and ensuring the smallest scar possible.HOW IS MOHS SURGERY DIFFERENT FROM OTHER TREATMENTS?

Often the tumor that is visible to you – even to your doctor – may be just the ‘tip of the iceberg’. The tumor may have roots or finger-like extensions of microscopic tumor cells that extend beyond the visible lesion. If these cancer cells are not completely removed they can lead to regrowth and recurrence of the tumor. Common treatments are often not successful because they rely on the naked eye to determine the extent of the cancer. In Mohs surgery, the extent of the cancer is determined microscopically, ensuring accurate and complete removal.

In a standard surgical excision, the tumor is excised along with a large margin of normal tissuearound it. This extra tissue is removed blindly with the hopes that these invisible microscopic tumor cells or roots will be removed with it. In some cases, this extra margin is not enough and microscopic tumor cells are left behind allowing for a possible recurrence; in other cases, this margin removes more healthy tissue than is necessary resulting in unnecessary scarring. The excised tissue is sent out to a pathology lab for delayed examination where about 1% of the tissue margin is examined to determine whether the margins are clear of cancer. Since only a small percentage (1%) of margins are evaluated, residual tumor may be missed. If more cancer cells are found in the margins during delayed pathologic examination, a second surgical procedure will be required at a later date.

Mohs micrographic surgery, so named for Dr. Frederick Mohs who created the technique in the 1930s, removes the guesswork and error inherent in standard excision. The Mohs technique, which has been refined and perfected over decades, enables the Mohs surgeon to see beyond the visible disease, and to precisely identify and remove the entire tumor, leaving healthy tissue unharmed. To begin, the visible tumor is removed with a small margin of normal tissue around it. The excised tissue is then carefully mapped, color-coded, and thoroughly examined with a microscope in real time – on the very same day. The Mohs surgeon examines 100% of the tissue margin to determine whether any tumor cells are left at the margins. If any microscopic tumor cells are present, the Mohs surgeon can determine precisely where they are and go back to remove additional tissue, just where it is necessary, sparing healthy tissue.

The entire Mohs procedure is performed under local anesthesia in the surgeon’s office and pathological examinations are immediate. The entire process is usually completed in a single day.WHO PERFORMS MOHS SURGERY?

Mohs surgery requires the specialized skill and training of a Mohs dermatologic surgeon. Mohs surgeons are board-certified dermatologists who have completed additional intensive fellowship training in all aspects of Mohs surgery including surgical removal of skin cancers, pathological examination of tissue and advanced reconstructive techniques. Fellowship-trained Mohs surgeons are recognized by the American College of Mohs Surgery (ACMS).

Mohs Surgery Silver Spring MD - Michelle Levender PicYour doctor, Dr. Michelle Levender, is a board-certified dermatologist and ACMS fellowship-trained Mohs Surgeon. She graduated with highest honors, Summa Cum Laude and Phi Beta Kappa, from the University of Richmond with a Bachelor of Science in Psychology and minors in Studio Art and Biology. She earned her Doctor of Medicine from the University of Maryland where she earned highest honors with election to the Alpha Omega Alpha Honor Society. She then went on to complete two years of residency training in Obstetrics and Gynecology at Pennsylvania Hospital in Philadelphia, during which time she delivered over 400 babies and performed countless surgeries. Despite a wonderful experience she made the difficult decision to leave Obstetrics and Gynecology behind to pursue her passion for Dermatology. Dr. Levender was awarded a competitive one year Clinical Research Fellowship at the Center for Dermatology Research at Wake Forest University in North Carolina. She then completed a rigorous residency program in Dermatology at Columbia University in New York City followed by an ACMS-accredited fellowship in Cutaneous Oncology, Mohs and Reconstructive Surgery, and Laser and Cosmetic Dermatology at the University of California, San Francisco (UCSF). Dr. Levender has published over 20 peer-reviewed articles and several textbook chapters and has presented at meetings around the world.PREPARING FOR SURGERY

3 weeks prior to surgery

  • If you smoke cigarettes or use tobacco products, discontinue these or cut back as much as possible. Smoking and tobacco use impairs wound healing and increases the rate of complications and infections after surgery.

2 weeks prior to surgery

  • Discontinue all non-essential over-the-counter medications, herbal medications and supplements unless they are being prescribed by your physician – these can act as blood thinners and increase the risk of bleeding during and after surgery. If a pain reliever is needed take Tylenol (acetaminophen).

1 week prior to surgery

  • Do not shave around the surgical site for 1 week prior to surgery – shaving in and around the area increases the risk of infection.

2 days prior to surgery

  • Avoid all alcoholic beverages – these act as blood thinners and increase the risk of bleeding.

Morning of surgery

  • Take a shower, wash thoroughly with Hibiclens (chlorhexidine) antibacterial soap and shampoo and wash your hair – this will minimize the chances of a postoperative infection
  • Dress in comfortable clothes
  • Eat a good breakfast
  • Take all of your prescribed medications

What you will need on the day of your surgery

  • You must have a ride arranged to bring you to and from surgery
  • A list of your current medications
  • Something to read or entertain yourself
  • Lunch
  • A sweater or jacket


You will be brought to the surgical suite by one of Dr. Levender’s surgical assistants who will review your medical history, check your blood pressure and identify the surgical site. Dr. Levender will then review the procedure with you and answer any questions you might have.

The first “stage” will begin in which Dr. Levender numbs the site with a local anesthetic. She will then excise the visible tumor as a shallow disk. A pressure bandage will be applied to the open wound. This whole process typically takes ~10-15 minutes and your experience of it will be very similar to the biopsy procedure. You will then return to the waiting room where light snacks and beverages are available.

Dr. Levender will make an anatomically-oriented map of the excised tissue, which she will ink and color-code to correlate with the map. The tissue is then brought to the lab where the tissue processing and slide preparation begins immediately. After the tissue is processed and slides are prepared and stained, Dr. Levender performs the microscopic evaluation to determine whether there are any tumor cells present at the margins of the excised tissue. This entire process is takes aminimum of 1 ½ to 2 hours.

If any tumor cells are identified at the margins, an additional stage is necessary and the process repeats: you are brought back to the surgical suite, the area is numbed with a local anesthetic andDr. Levender removes another thin layer of tissue – this time only in the precise location where the tumor cells were visualized with the microscope. This stage again takes ~10-15 minutes, after which a pressure bandage is applied to the wound and you return to the waiting room. As before, the tissue is mapped, color-coded and brought to the lab for tissue processing, slide preparation and microscopic evaluation. This processing and evaluation again takes a minimum of 1 ½ to 2 hours.

Mohs Surgery Silver Spring MD - visible lesionThe process continues and repeats, with subsequent stages, until the tumor is completely removed.

Once the cancer is completely removed, you will return to the surgical suite where Dr. Levender will perform the reconstruction. It is not possible to know how best to repair the wound until the entire tumor is out. In most cases, the wound is closed with stitches. The wound may be closed side to side in a line or a skin graft or skin flap may be necessary. In some cases the best healing may be achieved with no stitches at all. Dr. Levender will review the options with you and determine which type of repair will result in the best outcome.

Please Note:
Several surgical stages and microscopic evaluations are often required to remove your tumor. In between these stages, you will be asked to wait in the waiting room. This waiting can be the most difficult part of the day. Unfortunately, there is no way to predict how many stages will be necessary. In some cases the tumor is removed in one stage and your procedure may be completed before lunchtime. In other cases, multiple stages are necessary and your procedure will extend into the late afternoon or early evening. Because we cannot predict how much time will be required to clear your tumor and repair the wound, you should plan to spend the entire day in the office. Please do not make any other commitments for the day and make sure your ride is aware of this.


  • You will need to take it very easy for a minimum of 1-2 days after surgery.
  • In most cases you will have stitches in place that will need to be removed in 1 week (on the face) or 2-3 weeks (on the body).
  • You will have a lot of swelling and bruising in and around the surgical site for 7-10 days after surgery. If your procedure is on the forehead, eyelid, nose or cheek you will likely have a black eye that may even swell shut. This is normal.
  • You will need to avoid any exercise, heavy lifting or strenuous activity for 1-2 weeks following your surgery.
  • You will need to avoid any alcoholic beverages for 2 days after surgery and avoid any tobacco use for 3 weeks after surgery
  • You can resume over-the-counter medications, herbal medications and supplements 3 days after surgery
  • Complications, should they occur, will occur in the first 1-2 weeks after surgery. For this reason, we ask that you do not plan any travel for at least 2 weeks after your surgery.

You will receive more detailed written post-operative instructions including wound care instructions on the day of your surgeryHOW TO PROTECT YOURSELF IN THE FUTURE

  • After having one skin cancer you are at significantly higher risk of developing additional skin cancers – these are much easier to treat when they are caught early, so it is important to see your regular dermatologist every 6 months for full skin checks
  • Minimize your risk of future skin cancers by practicing safe sun: wear protective clothing (wide-brimmed hats, long sleeves), use sunscreen (SPF 30 or higher) on exposed areas, and minimize sun exposure during peak sun times (10am – 2pm)