Mohs Surgery Explained: What It Is and Who Performs It
What NCI and MedlinePlus say about Mohs surgery for skin cancer, which credentials Mohs surgeons may hold, and questions to ask before the procedure.
If a skin cancer has been found, you may hear the term "Mohs surgery." It is one of several ways to remove some skin cancers. This guide explains what official sources say about the procedure, who performs it and what to ask. It is general information, not medical advice. Your own doctor is the person to tell you which treatment fits your situation.
What Mohs surgery is
The National Cancer Institute (NCI) describes Mohs micrographic surgery in its patient summary on skin cancer treatment. The tumor is removed from the skin in thin layers. During the procedure, the edges of the removed tissue are checked under a microscope for cancer cells. The goal is to remove as little normal tissue as possible. NCI says it is often used for skin cancer on the face, fingers or genitals and for skin cancer that does not have a clear border.
MedlinePlus, from the National Library of Medicine, gives more detail in its article on Mohs micrographic surgery:
- It is usually done in a doctor's office or outpatient setting, and you stay awake. The area is numbed.
- The surgeon removes a thin layer, and the tissue is prepared and looked at under a microscope while you wait.
- If cancer remains at an edge, another layer is taken from that spot only. Each round takes about an hour, much of it for preparing and reading the tissue.
- It often takes two or more rounds, and the whole process is usually done in one day.
- Once the cancer is out, the wound may be left to heal, closed with stitches, or repaired with a skin graft or flap.
MedlinePlus lists possible complications, which it describes as rare, including infection, bleeding, numbness from nerve damage and raised scars (keloids). Ask the surgeon how these risks apply to you.
Which cancers it is used for
NCI lists Mohs surgery among the treatment options for basal cell carcinoma and squamous cell carcinoma of the skin, the two most common types of skin cancer. Other options NCI lists for basal cell carcinoma include simple excision, curettage and electrodesiccation, cryosurgery, radiation therapy, photodynamic therapy and topical treatments. MedlinePlus says Mohs may be used when tissue needs to be spared, such as on the face, hands or genitals, or when the risk of the cancer coming back is high.
Mohs is not used for every skin cancer, and it is not the only good option. The choice depends on the type, size and location of the cancer and on your health. That is a conversation to have with your dermatologist.
Who performs Mohs surgery
MedlinePlus says Mohs surgery is done by surgeons trained in the Mohs procedure. The American College of Mohs Surgery describes the method as combining surgery with examination of the tissue edges under a microscope, so training covers both. There are a few separate credentials to know about:
- ABD subspecialty certification. The American Board of Dermatology certifies dermatologists in the subspecialty of micrographic dermatologic surgery. The ABMS profile of the ABD describes this field as caring for patients with certain high-risk and complex skin cancers, removing and examining the tissue step by step until only cancer-free tissue remains, and repairing the wound. The ABD publishes lists of physicians who passed its Micrographic Dermatologic Surgery exam.
- AOBD subspecialty certification. The American Osteopathic Board of Dermatology offers certification in Mohs micrographic surgery for dermatologists who already hold its primary dermatology certification.
- Fellowship training. The American College of Mohs Surgery, a professional society, says on its patient page that its members are fellowship-trained, with a Mohs fellowship involving at least one year of surgical training. Its fellowship training page says fellowships run 1 to 2 years and that US programs are accredited by the Accreditation Council for Graduate Medical Education (ACGME).
Not every doctor who performs Mohs surgery holds every one of these credentials, and holding a credential does not guarantee a particular result. Use them as facts to check and ask about. Our guide on how to check a dermatologist's license and board certification shows where to look.
What a listing here can and cannot tell you
Some listings in this directory show the NPPES taxonomy "MOHS-Micrographic Surgery" or "Procedural Dermatology." Providers choose these codes themselves when they register for an NPI. A code is not a certificate and is not proof of training. We do not rate or recommend surgeons. Use a listing to find names, locations and NPI facts, then verify credentials with the boards.
Questions to ask before Mohs surgery
- Why is Mohs recommended for my cancer, and what other options are there?
- Are you certified in micrographic dermatologic surgery or Mohs surgery, and by which board? Did you complete a Mohs fellowship?
- Who reads the slides during the procedure?
- How long should I plan to be at the office? Can I eat beforehand, and should I bring someone to drive me?
- What should I tell you about my usual medicines, including blood thinners, before the procedure?
- How will the wound be closed? Will you do the repair, or will another surgeon?
- What will the scar likely look like, and what follow-up will I need?
- Is the procedure covered by my plan, and does it need prior authorization?
Cost and coverage
Medicare Part B covers medically necessary services, meaning services that meet accepted standards of medical practice to diagnose or treat a medical condition. Medicare generally does not cover cosmetic surgery. Coverage details still vary by plan, so ask before you schedule. Our guide to medical vs cosmetic dermatology and what Medicare covers explains assignment, Medicare Advantage networks and the questions to ask your plan.
After the procedure
Ask the surgeon for written wound-care instructions and a number to call with questions. If you think you have an emergency, call 911. Ask your dermatologist whether you need follow-up skin checks and how often. Our guide on preparing for a skin exam covers what to bring to those visits.
General information only, current as of the date above. The information on Dermatologist Index is not medical advice and does not replace a doctor, nurse, discharge planner or other qualified professional. Do not use it to make decisions about diagnosis or treatment. If you have a medical emergency, call 911. Rules and programs change; check the official sources linked in this guide.