Mohs Micrographic / PDEMA (formerly CCPDMA) Surgery

What is Mohs micrographic surgery and PDEMA?

Developed over 80 years ago by Dr Frederic Mohs, Mohs micrographic surgery remains the most advanced surgical method of skin cancer removal.

Mohs Micrographic Surgery is a specialised surgical technique used to remove skin cancer layer by layer while examining 100% of the margins under a microscope. This allows the surgeon to remove all cancerous cells while sparing as much healthy tissue as possible.

PDEMA is a modified Mohs technique that uses an “en face” evaluation of the margins. It is ideal for certain types of non-melanoma skin cancers and offers precise margin control with excellent cosmetic and functional outcomes.

Both techniques are performed in stages during a single visit, making them the gold standard for high-risk or recurrent skin cancers.

PDEMA (Peripheral and Deep En Face Margin Assessment) surgery is very similar to the Mohs procedure. However for PDEMA, a separate pathologist will read the slides for the surgeon – whereas in a Mohs procedure, the specialist in question serves as both surgeon and pathologist.

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What to expect for Mohs micrographic surgery and PDEMA?

If your skin cancer is being treated with Mohs surgery or PDEMA, these are the primary elements to be aware of going in:

• Local anaesthesia with our without sedation or general anaesthesia
• Surgical excision of cancerous tissue
• Microscopic examination of cut surfaces
• Higher cure rates than with standard excision
• Smaller defects than with standard excision
• Same day repair

Our Mohs micrographic / PDEMA surgeons are specially trained in this technique and perform both the surgery and the reconstruction. Because these methods require the surgeon to have highly specialised training, specific surgical and laboratory facilities and specialised personnel, few medical centres are equipped to offer such treatment.

Skin Institute is one of the few medical centres equipped and staffed with skilled personnel to offer these techniques, which boast the highest cure rates for skin cancer.

Because of the complex training and equipment needed to carry out the surgery, it’s a very specialised procedure – one that we are proud to be able to offer.

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When it’s recommended

Mohs micrographic / PDEMA surgery is used primarily to treat BCCs and SCCs but can also be used to treat less common tumours, including melanoma. Mohs micrographic surgery is indicated when:

• Skin cancers on the face, ears, lips, nose, or eyelids
• The cancer is large
• Recurrent skin cancers
• Skin cancers with poorly defined borders
• Aggressive, high-risk, or infiltrative subtypes
• Areas where preserving healthy tissue is vital

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What does it include?

Your treatment typically involves:

• Preoperative consultation and skin examination
• Precise surgical removal of cancer in staged layers
• On-site pathology review for immediate margin assessment
• Reconstruction or wound closure (if required)
• Post-operative care advice and follow-up

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What to expect (during & after)

During the procedure

• Local anaesthetic is used, so you remain awake but comfortable.
• The surgeon removes the first layer of tissue and examines it immediately.
• You may wait between stages while the tissue is analysed.
• Most Mohs procedures take a few hours, depending on the number of stages required.

After the procedure

• You can go home the same day.
• Mild swelling, tightness, or bruising is normal.
• Stitches may remain in place for 5–14 days depending on the location.
• Healing continues over several weeks, with scars typically improving over time.

Recovery & Aftercare

• Follow wound care instructions carefully to reduce infection risk.
• Avoid strenuous activities for several days.
• Keep the area clean and protected from the sun.
• Attend follow-up appointments to monitor healing.

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Risks & Considerations

While Mohs / PDEMA is extremely safe, possible risks include:

• Bleeding or infection
• Scarring (minimised through precise removal)
• Temporary numbness
• Rarely, incomplete removal requiring additional treatment

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Cost

To be quoted by provider

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FAQ

What is the success rate?

Mohs offers up to 99% cure rates for certain skin cancers.

Is the cancer removed in one day?

Yes – the full procedure, including pathology, is completed during your visit.

Is Mohs surgery painful?

Only local anaesthetic is used, so discomfort is minimal.