Skin cancer explainer: What is Mohs Surgery?

If you or someone close to you has been diagnosed with skin cancer you may well have heard of ‘Mohs Micrographic Surgery’. But what exactly is it? And why is it considered a gold standard treatment for skin cancer?

The natural reaction for anyone with a mole or lump that’s found to be skin cancer is to want it removed as soon as possible. As a dermatological surgeon, I always endeavour to do this. The sooner it is discovered, and the quicker it is removed, the better the outcome is likely to be.

But this is often a very worrying time for a patient and, understandably, it can be difficult to take in all the information they’re being told about treatment options and what they entail.

“What’s the surgical process? What does it involve? Will I have scars? How long will it take to heal? Will the cancer come back?”

Here is an overview of Mohs surgery – one of the best available treatments for skin cancer that I regularly perform on my patients. 

What is Mohs surgery?

Mohs micrographic surgery is a highly specialised technique to remove skin cancer, named after the surgeon who developed it. It’s considered to be the gold-standard treatment because it’s the least invasive and most effective. As such, it tends to be used on delicate areas of the body, such as the head, face, and neck, though it can be performed anywhere on the body. 

What happens during Mohs surgery? 

The procedure involves delicately removing a thin layer of the cancerous tissue and then examining it under a microscope to see if all of the cancer has been removed. The process repeats, layer-by-layer, until we are sure it is all gone. This can make the process a lengthy one – sometimes a matter of hours – but it ensures that all the cancerous tissue is removed while preserving the maximum amount of healthy skin. 

What happens after the procedure?

Once the Mohs procedure has been performed, the tumour is carefully evaluated and a reconstruction option is selected to achieve the best final cosmetic outcome for the individual patient. 

How does the skin heal after Mohs surgery?

There are a number of different methods to help the skin heal and repair as effectively as possible after the surgery. I always select the most appropriate one for my patient based on the size of the wound, where it is on the body, the principles of aesthetic design and a number of patient factors.

The repair methods include:

  • primary closure – where the skin of the wound is brought together into a linear scar and sutured closed.
  • Skin flaps – using skin adjacent to the wound to delicately cover it.
  • Skin grafts – using skin from another part of the body to repair the wound
  • Secondary intention – carefully attending to the wound to allow it to heal naturally over time.

Does Mohs surgery cause permanent scarring?

Many patients are worried about permanent scarring, particularly when the tumour being removed is large or when it is on a delicate and visible part of the body, such as the face. Although scarring is an unavoidable consequence of skin surgery, there are a number of aesthetic surgical techniques I use  to help optimise scar placement. These include: