What is Mohs Micrographic Surgery?

Mohs micrographic surgery is the most advanced and sophisticated method of treating skin cancer. It produces cure rates that are higher than for any other technique. This technique was devised almost 60 years ago by Dr. Frederic Mohs, at the University of Wisconsin. It was initially known as chemosurgery, but is now called Mohs micrographic surgery after its inventor.

What kind of skin cancers can Mohs Micrographic Surgery be used for?

The most common types of skin cancer to be treated by Mohs Micrographic Surgery are basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). However, other skin cancers such as DFSP (dermatofibrosarcoma protuberans), AFX (atypical fibroxanthoma) and sebaceous carcinomas are best treated with this technique.

How does skin cancer grow?

It is important to understand how skin cancers grow, as this in turn will help appreciate why Mohs Micrographic Surgery is so useful. Skin cancers begin in the uppermost layer of the skin (the epidermis) and grow to the sides on the surface of the skin and downward, below the skin surface, with root-like extensions. This is comparable to the roots of a weed.

 

Unfortunately, root-like extensions of skin cancer cannot be seen with the naked eye. Therefore, what is apparent to the naked eye on the surface of the skin may actually be only the visible ‘tip of the iceberg’. If the roots are not treated, then the skin cancer will likely recur. Mohs Micrographic Surgery helps ensure these roots are cleared away completely as removed tissue is examined under the microscope and the tumour is mapped so that guessing the extent of the tumour is eliminated. All other methods of skin cancer treatments require best guessing how wide and deep to treat.

How is Mohs Micrographic Surgery performed?

Mohs micrographic surgery involves surgical excision of cancer containing tissue and systematic microscopic examination of all cut surfaces at the time of the operation. It is a highly specialised procedure for the total removal of skin cancers. If the tests show that there is any cancer remaining, then further surgery is performed at the sites where cancer could be. The tissue is tested again and the procedure repeated until there is confidence that the whole tumour has been removed.

What kind of anaesthetic is required?

Mohs micrographic surgery is usually performed under local anaesthetic. This means the patient is awake during the whole procedure. It can also be performed under sedation if this is required.

How long does it take?

Complete removal of a skin cancer, which may involve several surgical stages, is usually completed in half a day. After the surgery, a decision is made as to the best way to manage the wound created by the surgery.

How effective is Mohs micrographic surgery?

Using the Mohs micrographic surgical technique, the cure rate for skin cancer is very high, often 95% to 98% – even if other forms of treatment have failed. This is the highest cure rate among all treatments available for treating common skin cancers.

What are the advantages of Mohs Micrographic Surgery?

• Mohs surgery has the highest cure rate for skin cancer.

 

• It is especially suited for poorly defined tumours, recurrent tumours and tumours known to behave in an aggressive manner.

 

• Mohs surgery provides the surgeon and patient with confidence that the tumour is completely removed prior to closure of the wound.

 

• With Mohs surgery, less adjacent normal skin is sacrificed resulting in smaller wounds and therefore smaller scars.

 

What are the disadvantages of Mohs Micrographic Surgery?

• Mohs surgery is more time consuming than routine surgery.

 

• It involves more staff and equipment and because it takes longer to perform, Mohs surgery is more expensive than routine surgery.

Will the surgery leave a scar?

Yes. Most forms of therapy will leave a scar. However, the Mohs micrographic surgery allows any scars to be as small as possible.

Wound repair

When we have determined that the skin cancer has been completely removed, a decision is made about what to do with the wound created by the surgery. Usually there are two choices: to let the wound heal by itself (‘granulation’) or to repair (close) the wound with stitches (either by bringing the wound edges together or with a skin flap or skin graft). We will discuss with you which of these choices will be best in your individual case.

It is impossible to tell with certainty prior to surgery, how deep or wide your wound will be. Although we have a general idea prior to Mohs micrographic surgery, we prefer to wait until the entire tumour is removed before thinking about whether to repair the wound immediately or what kind of repair to select. This concept is like walking over two bridges. One has to cross the first bridge before getting to the second bridge. Furthermore, it maybe preferable to wait for a few days after Mohs micrographic surgery before a repair is done. Some repairs are more likely to be successful if they are delayed.

What should I do next?

If you would like to discuss the treatment options for skin cancers, then please arrange an appointment to see Dr Martin-Clavijo.  Mohs micrographic surgery is usually covered by most insurance policies.