Mohs surgery





Definition

Mohs surgery, also called Mohs micrographic surgery, is a precise surgical technique that is used to remove all parts of cancerous skin tumors, while preserving as much healthy tissue as possible.


Purpose

Mohs surgery is used to treat such cancers of the skin as basal cell carcinoma, squamous cell carcinoma, and melanoma.

Malignant skin tumors may occur in strange, asymmetrical shapes. The tumor may have long finger-like projections that extend across the skin (laterally) or down into the skin. Because these extensions may be composed of only a few cells, they cannot be seen or felt. Standard surgical removal (excision) may miss these cancerous cells leading to recurrence of the tumor. To assure removal of all cancerous tissue, a large piece of skin needs to be removed. This causes a cosmetically unacceptable result, especially if the cancer is located on the face. Mohs surgery enables the surgeon to precisely excise the entire tumor without removing excessive amounts of the surrounding healthy tissue.

Mohs surgery is performed when:

  • The cancer was treated previously and recurred.
  • Scar tissue exists in the area of the cancer.
  • The cancer is in at least one area where it is important to preserve healthy tissue for maximum functional and cosmetic result, such as on the eyelids, the nose, the ears, and the lips.
  • The edges of the cancer cannot be clearly defined.
  • The cancer grows rapidly or uncontrollably.

Demographics

According to the National Cancer Institute (NCI), about one million people in the United States are diagnosed with skin cancer every year. The two most common types of skin cancer are basal cell carcinoma and squamous cell carcinoma, with basal cell carcinoma accounting for more than 90% of all of skin cancers.

Melanoma is the most serious type of skin cancer. Each year in the United States more than 53,600 people are diagnosed with melanoma, and it is becoming more and more common, especially among Western countries. In the United States, the percentage of people who develop melanoma has more than doubled in the past 30 years.


Description

There are two types of Mohs surgery: fresh-tissue technique and fixed-tissue technique. Of the surgeons who perform Mohs surgery, 72% use only the fresh-tissue technique. The remaining surgeons (18%) use both techniques. However, the fixed-tissue technique is used in fewer than 5% of patients. The main difference between the two techniques is in the preparatory steps.


Fresh-tissue technique

Fresh-tissue Mohs surgery is performed under local anesthesia for tumors of the skin. The area to be excised is cleaned with a disinfectant solution and a sterile drape is placed over the site. The surgeon may outline the tumor using a surgical marking pen, or a dye. A local anesthetic (lidocaine plus epinephrine) is injected into the area. Once the local anesthetic has taken effect, the main portion of the tumor is excised (debulked) using a spoon-shaped tool (curette). To define the area to be excised and to allow for accurate mapping of the tumor, the surgeon makes identifying marks around the lesion. These marks may be made with stitches, staples, fine cuts with a scalpel, or temporary tattoos. One layer of tissue is carefully excised (first Mohs excision), cut into smaller sections, and taken to the laboratory for analysis.

If cancerous cells are found in any of the tissue sections, a second layer of tissue is removed (second Mohs excision). Because only the sections that have cancerous cells are removed, healthy tissue can be spared. The entire procedure, including surgical repair of the wound, is performed in one day. Surgical repair may be performed by the Mohs surgeon, a plastic surgeon, or another specialist. In certain cases, wounds may be allowed to heal naturally.


Fixed-tissue technique

With fixed-tissue Mohs surgery, the tumor is debulked, as described previously. Trichloracetic acid is applied to the wound to control bleeding, followed by a preservative (fixative) called zinc chloride. The wound is dressed and the tissue is allowed to fix for six to 24 hours, depending on the depth of the tissue involved. This period, called the fixation period, can be painful to the patient. The first Mohs excision is performed as described; however, anesthesia is not required because the tissue is dead. If cancerous cells are found, fixative is applied to the affected area for an additional six to 24 hours. Excisions are performed in this sequential process until all cancerous tissue is removed. Surgical repair of the wound may be performed once all fixed tissue has sloughed off—usually a few days after the last excision.


Diagnosis/Preparation

An oncologist will have diagnosed the skin cancer of the patient using such standard cancer diagnostic tools as biopsy of the tumor.

To prepare for surgery, and under certain conditions (such as the location of the skin tumor or health status of the patient), antibiotics may be given to the patient prior to the procedure; this is known as prophylactic antibiotic treatment. Patients are encouraged to eat prior to surgery and also to bring along snacks in case the procedure become lengthy. To reduce the risk of bleeding, the use of nonsteroidal anti-inflammatory drugs (NSAIDs), alcohol, vitamin E, and fish oil tablets should be avoided prior to the procedure. The patient who uses over-thecounter aspirin or the prescription blood-thinners, brands Coumadin (warfarin, generically) and heparin should consult with the prescribing physician before adjusting the dosage of any drug.


Aftercare

Patients should expect to receive specific wound care instructions from their physician or surgeon. Generally, however, wounds that have been repaired with absorbable stitches or skin grafts should be kept covered with a bandage for one week. Wounds that have been repaired using nonabsorbable stitches should also be covered with a bandage that should be replaced daily until the stitches are removed one to two weeks later. Signs of infection (e.g., redness, pain, drainage) should be reported to the physician immediately.


Risks

Using the fresh-tissue technique on a large tumor requires large amounts of local anesthetic that can be toxic. Complications of Mohs surgery include infection, bleeding, scarring, and nerve damage.

Tumors spread in unpredictable patterns. Sometimes a seemingly small tumor is found to be quite large and widespread, resulting in a much larger excision than was anticipated.

Normal results

Most skin cancers treated by Mohs surgery are completely removed with minimal loss of normal skin.


Morbidity and mortality rates

Mohs surgery provides high cure rates for malignant skin tumors. For instance, the five-year cure rate for basal cell carcinoma treated by Mohs surgery is higher than 99%. The frequency of recurrence is much lower with Mohs surgery is much lower than with conventional surgical excision—less than 1%.


Alternatives

Mohs surgery is a specialized technique that is not indicated for the treatment of every type of skin cancer, and is most appropriately used under specific, well-defined circumstances. The majority of basal cell carcinomas can be treated with very high cure rates by standard methods, including electrodesiccation and curettage (ED&C), local excision, cryosurgery (freezing), and irradiation.

See also Cryotherapy .


Resources

BOOKS

PERIODICALS

Cook, J. L., and J. B. Perone. "A prospective evaluation of the incidence of complications associated with Mohs micrographic surgery." Archives of Dermatology 139 (February 2003): 143-152.

Jackson, E. M., and J. Cook. "Mohs micrographic surgery of a papillary eccrine adenoma." Dermatologic Surgery 28 (December 2002): 1168-1172.

Smeets, N. W., Stavast-Kooy, A. J., Krekels, G. A., Daemen, M. J., and H. A. Neumann. "Adjuvant Cytokeratin Staining in Mohs Micrographic Surgery for Basal Cell Carcinoma." Dermatologic Surgery 29 (April 2003): 375-377.

ORGANIZATIONS

American Society for Mohs Surgery. Private Mail Box 391, 5901 Warner Avenue, Huntington Beach, CA 92649-4659. (714) 840-3065. (800) 616-ASMS (2767). http://www.mohssurgery.org .

OTHER

"About Mohs Micrographic Surgery." Mohs College. http://www.mohscollege.org/AboutMMS.html .


Belinda Rowland, Ph.D.
Monique Laberge, Ph.D.

WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?


Mohs surgery is performed in a hospital setting by highly trained surgeons who are specialists both in dermatology and pathology. With their extensive knowledge of the skin and unique pathologic skills, they are able to remove only diseased tissue, preserving healthy tissue and minimizing the cosmetic impact of the surgery. Only physicians who have also completed a residency in dermatology are qualified for Mohs surgical training. The surgery is very often performed on an outpatient basis, usually in one day.

QUESTIONS TO ASK THE DOCTOR


  • How long have you been performing Mohs surgery?
  • Will you use the fresh-tissue or fixed-tissue technique?
  • Will I have to alter the use of my current medications for this procedure?
  • What will you do if you don't find the border of the cancerous lesion?
  • How will the wound be repaired?
  • Will I need a plastic surgeon to repair the wound?
  • What is the cure rate for this type of cancer when treated by Mohs surgery?
  • What is the chance that the tumor will recur?
  • How often will I have follow-up appointments?

User Contributions:

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Jul 26, 2010 @ 3:15 pm
Hello, I would like to learn more about Mohns Surgery. Please give me the opportunity to learn more about this disease. I am a surgical technologist looking for more information about this Surgery.
ellen
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Dec 5, 2010 @ 4:16 pm
I had successful Moh's Surgery Oct. 11. I now have a bubble like area on the inside of my nose underneath where the surgery was. It seems to be getting bigger (a little smaller than my nostril but it is on the side). It doesn't cover my nostril but affects my breathing slightly on that side. It does not hurt and it is not bleeding or draining. Should I be concerned? I don't want to go to the doctor and waste my money if it is nothing.
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Feb 1, 2011 @ 11:23 pm
My dad has a large cancerous tumor on his back and was diagnosed with squamous carcinoma. Can this moh surgery be used and are you limited with the size of the tumor.
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Feb 7, 2011 @ 9:09 am
The decision to have a cosmetic plastic surgery is extremely personal and you'll have to decide if the benefits will achieve your goals and if the risks and potential complications are acceptable. Your plastic surgeon and his/ or her staff will explain in detail the risks associated with surgery. You will be asked to sign consent forms to ensure that you fully understand the procedure you will undergo and any risks and potential complications.
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Sep 30, 2011 @ 1:01 am
I have the same or similar problem as Ellen above. Surgery 8 weeks ago for small basal cell on side of nose. i now have a small lump of ?scar tissue on inside of nostril that seems to be enlarging. it affects my breathing and is slightly uncomfortable like a clothespin pinching one side. Will this go away. Is it permanent. do i need a plastic surgeon. I am very upset as it makes me feel claustrophobic. Will this deformity go away?
susan shaffer
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Feb 6, 2012 @ 5:17 pm
I had mohs surgery on my knee the first tissue excised did not remove all of the cancer, the surgeon returned 1 hour later and use dirty instruments on me for the second excision. Is it possible to transfer cancer cells fomr diseased tissue to healthy tissue?
Linda
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Jul 29, 2012 @ 4:16 pm
My husband is scheduled for this surgery on his cheek this week. We will have to travel 2 hours to the facility. My husband takes Effient blood thinner and has not communicated this to the out of town surgeon. Do we need to discuss this before we go? He also takes an aspirin daily - 81 mg and cholesterol med as well as several types of otc supplements including fish oil. Thanks!
Helen Hurst
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Mar 15, 2013 @ 12:12 pm
Had Mohs surgery but the surgeon sent a piece of tissue to a lab anyway. Why?
jean
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Nov 27, 2013 @ 3:15 pm
I had Mohs surgery on my nose 5 weeks ago with a follow-up visit 3 weeks ago. The wound looks better and I was advised to continue applying vasoline until the wound flattens out. When does the risk of infection go away?
Charles
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Jan 18, 2014 @ 10:10 am
I recently had Mohs surgery and was advised to use Bacitracin to aid in the healing. The skin around the incision started to form blisters and I was told to stop using it. Now the skin in the area of the blistering has turned black.Should I be concerned and will this area heal properly or will I have to have another surgery to correct this issue.
Neil K. Campbell
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Apr 22, 2014 @ 9:21 pm
I had Mohs surgery on my nose about a month ago. I have two or three major concerns to ask you about.
#1- My forehead and nose are still numb,I've been assured that this will go away.How long will this take? #2- My left nostril is raised up & a little puggish looking. Again I've been told this too will
return to normal. When? #3- My sinus's run more than normal. Will this go away? My worst fear is that
the nostril will stay the way it is and I'll live out My time looking just a little bit FREAKISH,so to speak! Please tell me I'm just being paranoid. Other than that, the procedure was a success.

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