Mohs Surgery

[subtitle]The Complete Guide to Mohs Surgery[/subtitle]

Considered the most effective method for removing squamous cell and basal cell carcinoma, Mohs surgery spares healthy skin tissues while eradicating all signs of cancerous activity. According to the American Cancer Society, cure rates for SCC and BCC are nearly 99 percent when the Mohs technique is used to remove these two most common types of skin cancers.

Dr Frederic Mohs

Dr Frederic Mohs

Developed nearly 80 years ago by Dr. Frederic Mohs, a general surgeon specializing in the excision of abnormal skin lesions, Mohs surgery is considered a “microscopically controlled” invasive procedure that involves a pathologist (usually the surgeon performing the tissue removal) examining each piece of tissue for evidence of cancer cells. Continuation of the surgery depends on whether a section of tissue contains cancer cells or appears normal under the microscope. This avoids unnecessary removal of healthy tissue while reducing the risk of infection and accelerating the healing process.

Mohs surgery is also used to remove sebaceous carcinomas, merkel cell carcinoma, angiosarcoma and atypical fibroxanthoma, especially when these skin diseases and SCC/BCC are located on the feet, face, genitals, lips, ears, hairline and hands. It is important to remain aware of certain limitations to Mohs surgery, such as the fact this type of micrographic surgery is generally reserved to treat recurring skin cancers or cancers that have been deemed a high risk for recurring by the patient’s physician.

What is Basal Cell and Squamous Cell Carcinoma?

Nearly 80 percent of all skin cancers are diagnosed as basal cell carcinoma, which means that these cancer cells resemble cells that are found at the very bottom of the epidermis, or the basal cell layer of the skin. Development of basal cell carcinoma is primarily due to excessive exposure to sunlight and is most commonly found on the neck, scalp and facial areas. Because basal cell skin cancer tends to recur after removal and even emerge elsewhere on the body, Mohs surgery is strongly indicated when treating this type of skin cancer.

About 20 percent of skin cancers are squamous cell carcinomas, so-called because the cancer cells composing squamous lesions look like abnormally shaped, squamous cells located in the upper layers of the skin. Like basal cell carcinomas, squamous cell carcinomas develop on areas of the body exposed to excessive UV radiation but also emerge within chronic sores and scars.

Benefits of Mohs Surgery over Excision Techniques

  • When surgeons excise a cancerous lesion without engaging in microscopic examination of tissue removed, the amount of healthy tissue is typically much more than is needed, since the surgeon is more concerned about removing all cancer cells and would rather remove extra tissue to ensure the totality of the cancer is eliminated. Using Mohs techniques, dermatological surgeons can control the depth and size of lesion removal so that some wounds result in resembling minor scrapes rather than invasive incisions.
  • By inventing the “sectioning method” of SCC and BCC removal, Dr. Mohs was able to incorporate comprehensive investigation of surgical margins in contrast to the “bread loafing” method of sectioning and sampling of random selections.
  • Patients undergoing Mohs surgery do not have to enter a hospital. Instead, the procedure is performed at Mayoral Dermatology using local anesthetics. Strong numbing agents minimize discomfort and patients remain awake and alert during treatment.
  • Because dermatological surgeons can employ specific mapping techniques when using Mohs, they are capable of pinpointing areas that would otherwise remain invisible without a microscope. This allows even the smallest cancer roots to be entirely removed with as little damage to healthy skin as possible.
  • The results of pathology reports ordered during traditional skin cancer surgery can take up to several days or weeks, a delay that allows the wound to begin healing. This means that if results come back positive, the area would suffer further trauma by needing to be reopened. With the Mohs technique of examining tissue as it is removed, skin cancers are completely eliminated prior to the initiation of healing.

How Mohs Surgery is Performed

After anesthetizing the area, the surgeon uses a small scalpel to cut around the lesion or tumor, generally within 1.5 millimeters of the skin area not involved with the cancer. The standard “free margin” amount used in non-Mohs surgery is about six millimeters.

Each specimen removed is cut on a cryostat (a device that maintains a very low temperature), set on microscope slides and stained with special dye solutions to visibly enhance abnormal cell activity. When cancer is discovered by the pathologist, the site of the cancer is designated on a map of the tissue, which the surgeon refers to as he continues removing cancerous tissues. The surgeon continues slicing very thin layers of the lesion away until the pathologist no longer sees any cancer in the tissue specimens provided by the surgeon.

One consequence of Mohs surgery is that most people experience varying degrees of scarring that requires reconstructive surgery, especially if the lesion removed was on the face. Repair of scarring is typical done the same day Mohs was performed.
Healing of skin after Mohs surgery peaks around six weeks following the procedure and initially appears as a hardening the scar. This bumpiness is temporary and most scars soften and may even improve in time. People with a propensity for scarring easily or developing keloids or hypertrophic scars will probably experience worse scars than other who do not have problems with scars.

The American College of Mohs Surgery

American College of Mohs Surgery

American College of Mohs Surgery

The ACMS ( is an organization comprised of dermatologists who specialize in Mohs surgery and dermatology. Member of this organization adhere to standards of care set by the College for fellowship-trained surgeon-dermatologists who employ Mohs techniques in their practice. Completing an American College of Mohs Surgery fellowship requires fours years of residency and up to two years training in Mohs procedures as well as training in plastic and reconstructive surgery. Primary care physicians consider Mohs surgeons belonging to the ACMS as expert specialists for performing Mohs surgery.

Mayoral Dermatology’s Dr. Manual Iriondo, MD

Dr. Manuel Iriondo

Dr. Manuel Iriondo

Board certified dermatologist Dr. Manuel Iriondo, M.D., is a specialist in Mohs surgery and a Fellow of the American College of Mohs Micrographic Surgery. Dr. Iriondo treats patients at Mayoral Dermatology who have been diagnosed with squamous or basal cell carcinoma using the latest Mohs techniques and can also perform reconstructive surgery when necessary.

Dr. Iriondo discusses Skin Cancer Prevention with Ron Magill on CBS News

Mayoral Dermatology 305-665-6166 6705 SW 57th Ave., Suite 314, Coral Gables, FL 33143
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