A new micrographic surgery for the treatment of skin cancer is proving to have an impressive cure rate.

Skin cancer is one of the most common forms of cancer. Fortunately, a highly targeted treatment that offers greater accuracy is now available in the form of Mohs micrographic surgery. 

Mohs micrographic surgery allows a surgeon to remove as little healthy tissue as possible while minimising the risk of skin cancer recurring. The practice was introduced in South Africa in 2017 and, since then, has come to be recognised as the gold standard in the treatment of skin cancer. The name “Mohs” is in honour of American physician Dr Frederic Mohs, who pioneered this type of skin cancer surgery more than 80 years ago.

What is micrographic surgery?
3D illustration of a cross-section of skin with melanoma that enters the bloodstream and lymphatic tract.

What makes this treatment so different from traditional treatments such as surgical excision of tumours, curettage and electrodessication, or radiation? For a start, says Dr Frits Spruyt, a plastic and reconstructive surgeon at Mediclinic Kloof, it enables doctors to see whether all cancer has been removed during an excision by providing a 360° view of the affected tissue.

This is because in each procedure the dermatologist removes minute layers of skin, which are examined under a microscope. In this way, it becomes possible to see if the skin is completely cancer-free, or if there are still remnants of the tumour left behind. If so, the patient returns to the operating theatre to have it removed. When the dermatologist is sure the excision site is completely clear, a plastic surgeon can start reconstructing the wound.

Why is it better?

The greatest advantage of this technique is that it proves with greater accuracy that a tumour has been completely removed.

Removal is also more effective, says Dr Spruyt: “We typically see recurrence rates of less than 1% with Mohs surgery, whereas this margin is slightly higher at 3% with a traditional excision. This is due to more accurate margins.”

Plus, the patient returns to theatre for reconstruction on the same day, knowing that the skin cancer has been removed before closure.

Are there any drawbacks?

Mohs surgery isn’t appropriate for all types of cancer. Dr Spruyt says it’s usually reserved for high-risk areas like the eyelids, ears, nose, and temples, or where the treating doctor wants to minimise scarring. It’s also used to treat high-risk lesions (those which are especially large, for instance); recurrent cancers; or tumours with aggressive growth patterns of basal cell or squamous cell carcinomas.

Patients who are candidates for the surgery should also be prepared for a long procedure. Dr Spruyt warns that while a traditional excision can take around 45 minutes, Mohs surgery may require an entire day. This is because the patient has to wait for the results from the microscopic examination after the excision (which itself is a complicated process, as the surgery is usually employed for high-risk lesions that may require several excisions). The reconstruction that follows adds further waiting time to the procedure.

What else do you need to know?

Mohs surgery takes place under local anaesthetic – another advantage, as this is less invasive than a traditional excision and no intubation is necessary. Reconstruction, meanwhile, takes place mostly under conscious sedation. Dr Spruyt explains this is necessary because this part of the procedure entails more movement of tissues and more extensive incisions. 

Patients are able to return home the same day as the procedure.

Where to from here?

Mohs surgery has already evolved considerably since the technique was first developed: in the early days, you had to stay in theatre until the outcome of the microscopic examination was announced. Now, you can look forward to a more comfortable wait in the recliner ward.

The surgery has also become more affordable, and therefore accessible, over time.

Can we look forward to further developments in this field?

Quite possibly, Dr Spruyt says, adding that he’d like to see the technique made applicable to more types of cancers. In the meantime, though, Mohs surgery is certain to become an entrenched part of the care circle, which in turn will help practitioners to avoid either over- or under-treating patients. 


Skin cancer is one of the most common forms of cancer. According to the World Health Organization (WHO), the incidence of the two main categories of skin cancer – melanoma (malignant melanoma) and non-melanoma – has been increasing over the past decades. It estimates that a 10% decrease in ozone levels will result in an additional 300 000 non-melanoma and 4 500 melanoma skin cancer cases globally.

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