The Mohs Effective Treatment for Skin Cancer

Healthy Valley Magazine cover for the August 2013 Issue

It’s summertime and almost every magazine and TV news program has a report on the harmful effects of the sun’s UV radiation and its role in the development of skin cancer.

We learn about the latest products for sun protection, the most effective sunscreen ingredients, and techniques on how to best protect ourselves. But what if you saw your Dermatologist recently, had a skin biopsy, and just found out you have a skin cancer? What if you have one of the 3.5 million skin cancers that will be diagnosed this year in the US? Now your question is no longer about prevention but how to treat your skin cancer. What are the best treatments currently available for skin cancer and what is Mohs surgery?

Living in South Florida, many of us know someone who has had Mohs surgery. We may have heard the term ‘Mohs’ but are not really sure what it means. Is it mole surgery? Is MOHS an acronym which stands for a multi-word medical procedure because it is often (although incorrectly) capitalized? These are several commonly asked questions when people first hear the term Mohs surgery. Mohs is not a word that has a definition because it is actually someone’s last name. That someone is Dr. Frederick E. Mohs who developed this specialized technique of skin cancer surgery in the 1930’s. Using a microscope, we can evaluate a specimen of skin that contains skin cancer, see the growth pattern of the tumor within the skin, and examine all of the margins to make sure all of the skin cancer is removed. The procedure most commonly occurs in an outpatient setting, typically in a Dermatologist’s or Mohs surgeon’s office, the office will have a licensed laboratory where the skin cancer specimens are processed, and the entire surgery is performed using local anesthesia.

To begin the Mohs procedure, the area of skin containing the skin cancer is numbed using local anesthesia. The Mohs surgeon then uses a scalpel to remove the visible tumor plus a small margin of surrounding normal skin (commonly referred to as a ‘Mohs layer’). The goal is to have taken enough of a specimen that the tumor is completely removed and all the margins (both width and depth) are clear. The removed skin sample is then brought to the in-office laboratory where it is oriented and mapped so that it corresponds to the same anatomic orientation on the patient. This is a critical step of the procedure because it enables tumor cells seen under the microscope to be precisely correlated with the exact location on the patient’s surgical site. Depending on the size of the skin specimen, it takes approximately 15- 45 minutes to process and convert the skin sample into pathology slides. The Mohs surgeon then reads the pathology slides looking for any presence of tumor. The use of the microscope is the most important component of the procedure because:

  1. Individual tumor cells are so small that they are not visible to the naked eye and
  2. skin cancers grow with extensions or ‘roots’ so the microscope assists with tracking out the unique growth pattern of each skin cancer tumor.

If any tumor is noted, the Mohs map is marked in the area corresponding to the same area on the patient. The Mohs surgeon then returns to the patient, adds more local anesthetic if necessary, and takes another Mohs layer only in the area where tumor remains. In this manner, this technique removes all of the abnormal tissue and spares as much normal skin as possible. This process will be repeated until no further tumor is observed under the microscope and what we call ‘clear margins’ are obtained. It is because of this methodical examination of the surgical margins, that Mohs surgery offers cure rates up to 99% for the treatment of basal cell carcinoma and squamous cell carcinoma, the two most common forms of skin cancer. There are currently no other available treatment options for any type of skin cancer that provide these impressively high cure rates.

So, how do you know if your skin cancer needs Mohs surgery? There are many effective treatments for skin cancer: electrodessication and curettage (a “scraping and burning” procedure); topical creams; surgical excision; Mohs surgery; radiation; and in very advanced cases, an oral medication. The most common indications for treating a skin cancer using Mohs surgery are:

  1. LOCATION ON THE HEAD AND NECK (particularly nose, ear, eyelid and lip, areas that have important functions and are cosmetically sensitive where you want to preserve as much normal skin as possible).
  2. SIZE (greater than 1 cm on the face or 2 cm on the body).
  3. RECURRENCE (was treated by another method but has come back).
  4. AGGRESSIVE PATHOLOGY or RAPIDLY GROWING OR ILL-DEFINED BORDERS. Once your skin cancer has been removed using Mohs surgery, a discussion is had between you and your Mohs surgeon on how best to stitch close the wound or if it is best to allow the wound to heal by itself. Your surgeon will also discuss any restrictions with respect to medications you can take and if you may resume exercise. Again, since this procedure is performed using local anesthesia, most patients are bandaged and return to work and their normal daily routine immediately after surgery.

It is important to discuss with your doctor which treatment would be most appropriate for the type of skin cancer you have. Please see your Dermatologist regularly and remember, if diagnosed early and treated promptly, most forms of skin cancer are easily treated and curable. For more information about skin cancer and treatment using Mohs surgery, two excellent patient-friendly websites are and

View the full article The Mohs Effective Treatment for Skin Cancer.

Indulge Magazine feature of Dr. Alysa Herman

Dr. Herman is honored as one of Miami’s Top Doctors by Indulge Magazine, highlighting her as one of the city’s few dermatalogic surgeons specializing in Mohs micrographic surgery for skin cancer.

Indulge Top Doc 2017 Indulge Top Doc 2020
Map illustration of Dr. Alysa Herman's office
Back to Top