Mohs Surgery for Skin Cancer

Mohs surgery involves removing the visible skin cancer and layers of adjacent skin and soft tissue to facilitate microscopic examination of the excised tissue. Meticulous maps are created to follow tumor extensions, and excisions are sequentially continued until no cancer cells are evident upon microscopic examination. The surgical wound is then repaired, or allowed to heal by secondary intention to preserve as much form and function as possible. Mohs micrographic surgery – developed in the 1930s by Dr. Frederic Mohs – offers the highest cure rates in the treatment of basal cell and squamous cell cancers of the skin.

What to expect after the procedure

Most patients are able to drive themselves home following the procedure. Pain associated with the procedure typically is minimal and temporary. Your doctor may advise you to take an over-the-counter pain reliever or a prescription pain-reducing medication if necessary. Limitations on physical activity depend largely on the extent of the surgical procedure. Patients whose wounds were repaired with stitches will typically need to return to the doctor's office within one to three weeks for their removal.

How to prepare for the procedure

Before the procedure, an ASDS dermatologist will review the patient’s medical history and discuss expectations, potential risks/benefits and outcomes of the procedure. Patients should alert their doctor regarding their use of prescription and over-the-counter medicines and supplements.

What you should know about Mohs surgery for skin cancer

Mohs surgery often is used in the treatment of skin cancers on the face, scalp, hands, feet and genitals, though it also can be used on other areas of the body. The procedure typically is performed under local anesthesia in the doctor’s office. 

Mohs surgery uses a precise technique to sequentially remove layers of skin and adjacent soft tissue. The excised layers of tissue are frozen, stained with special dyes and then examined under the microscope to determine if they contain remaining cancer cells. If more cancer cells are present, an additional skin layer is then removed and examined. Repeated removals of skin are limited to areas in which cancer cells remain. This sequential excision procedure continues until microscopic examinations confirm that the skin cancer has been completely removed. 

After the skin cancer has been removed, the surgeon treats the wound in a manner that will promote both good healing and preservation of appearance. Wound treatment methods include: 

  • Allowing the wound to heal naturally.
  • Closing the wound simply with stitches.
  • Cover the wound with skin from another area of the body (skin graft) or from adjacent area (skin flap).

Why choose Mohs surgery for skin cancer?

Mohs surgery is the most effective treatment for basal cell and squamous cell carcinomas, and it also works much better than conventional treatments for a number of less common skin cancers, including melanoma. Cure rates for many types of skin cancers are 98-99 percent using Mohs surgery – significantly higher than with other treatment methods. 

Since tissue is removed only until the cancer is no longer present, the Mohs surgical procedure minimizes the size of the surgical wound required for skin cancer treatment and reduces the size and appearance of the resulting surgical scar.


Top: Before Mohs surgery; middle: Mohs defect; bottom: with sutures after Mohs surgery.

Photo courtesy of Andrew H. Weinstein, MD, MPH - Boynton Beach, FL

Before and after surgery with sutures.

Photos courtesy of Andrew H. Weinstein, MD, MPH - Boynton Beach, FL

Before and after surgery with sutures.

Photo courtesy of Andrew H. Weinstein, MD, MPH - Boynton Beach, FL

Find a doctor for your Mohs surgery

Visit "Find a Dermatologic Surgeon" and choose “Mohs Micrographic & Reconstructive Surgery” from the Procedures list. Because ASDS dermatologists are board-certified and trained in the best and latest techniques, they are the most qualified to evaluate and select the best treatment choice based on the individual patient’s condition.

Possible Risks

While Mohs surgery is typically a very safe and effective minor surgical method, all medical procedures carry some risk, though they are minimized in the hands of a qualified ASDS dermatologist. Risks include:

  • Bleeding
  • Scarring
  • Discoloration
  • Nerve damage
  • Pain
  • Cancer recurrence
  • The need for additional reconstructive surgery