What is Mohs Skin Cancer Surgery?
Mohs surgery, also called Mohs micrographic surgery, is a precision surgical technique that is used to remove all parts of cancerous skin tumors, while at the same time preserving as much healthy tissue as possible. Cancer cells can spread deep into the skin and almost tentacle-like, spread out and away from the superficial mole or bump on your skin. Removing all of the affected tissue is crucial to success. One small cell left behind can start a cascade of new cancer growth. Mohs surgery offers effective techniques for discovering and removing all the “bad” cells.
Dr. Sikorski is a member of the American Society for Mohs Surgery and has the special training qualifications required to perform this highly effective surgery for Orange County patients.
How is Mohs different from other types of skin cancer surgery?
The principle behind Mohs surgery is to remove all cancerous cells while minimizing removal of healthy tissue. Without Mohs, your doctor will excise the area of suspected cancer, send it to a lab, and wait several days for a lab report to find out if all the margins were clear of cancer cells. Because until that point it is not known if you will need additional excision, the area is left “open”.
If the pathologist verifies that all the cancer is removed, then your doctor will call you back (or send you to a cosmetic surgeon) to have the gap closed. If the pathologist says that there is still cancer visible in the specimen they received, then you will return to your doctor’s office, have more skin removed, and repeat the process. Mohs makes the process one step and allows closure or reconstructive work to be begin right away.
How is Mohs surgery done?
Mohs skin cancer surgery allows for the tissue to be examined through a microscope at the same time as the surgical removal to ensure that all of the cancer cells have been removed adequately. The surgical removal proceeds along a grid pattern with each layer carefully identified and mapped by the surgeon so that its exact location can be pinpointed on the wound. If any cancer cells are seen under the microscope, Dr. Sikorski can go back to that exact area and remove more tissue.
During this process, 100% of tissue margins are evaluated to ensure that the tumor is completely removed prior to repair of the skin defect in our office in the Orange County area, the resulting defect (hole or gap created from removing the cancer) will be closed and/or reconstruction started by Dr Sikorski right away.
Steps in the Mohs surgery
Step 1: Anesthesia
The tumor site is locally infused with anesthesia to completely numb the tissue. General anesthesia is not required for Mohs micrographic surgery.
Step 2: Stage I – Removal of visible tumor
Once the skin has been completely numbed, the tumor is gently scraped with a curette, a semi-sharp, scoop-shaped instrument. This helps define the clinical margin between tumor cells and healthy tissue. The first thin, saucer-shaped “layer” of tissue is then surgically removed by dermatologist Dr. Sikorski. An electric needle may be used to stop the bleeding.
Step 3: Mapping the tumor
Once a “layer” of tissue has been removed, a “map” or drawing of the tissue and its orientation to local landmarks (e.g. nose, cheek, etc) is made to serve as a guide to the precise location of the tumor. The tissue is labeled and color-coded to correlate with its position on the map. The tissue sections are processed and then examined to thoroughly evaluate for evidence of remaining cancer cells. It takes approximately 60 minutes to process, stain and examine a tissue section. During this processing period, your wound will be temporarily bandaged while waiting for results.
Step 4: Additional stages – Ensuring all cancer cells are removed
If any section of the tissue demonstrates cancer cells at the margin, Dr. Sikorski will return to that specific area of the tumor, as indicated by the map, and removes another thin layer of tissue only from the precise area where cancer cells were detected. The newly excised tissue is again mapped, color-coded, processed and examined for additional cancer cells. If microscopic analysis still shows evidence of the disease, the process continues layer-by-layer until the cancer is completely removed.
This selective removal of tumors allows for the preservation of much of the surrounding normal tissue. Because this systematic microscopic search reveals the roots of the skin cancer, Mohs surgery offers the highest chance for complete removal of cancer while sparing the normal tissue. Cure rates typically exceed 99% for new cancers, and 95% for recurrent cancers.
Step 5: Reconstruction
Trained Mohs surgeons are skilled in the reconstruction of skin defects. Reconstruction is individualized to preserve normal function and strive to maximize aesthetic outcomes. The effeective method of repairing the wound following surgery is determined only after the cancer is completely removed, as the final defect cannot be predicted prior to surgery. Stitches may be used to close the wound side-to-side, or a skin graft or a flap may be designed. Sometimes, a wound may be allowed to heal naturally.