Your first Mohs surgery appointment can feel unfamiliar because treatment involves both surgery and laboratory checks on the same day. Knowing what happens from arrival through to wound repair can make the experience less daunting and help you prepare for the waiting periods involved.

Before the Surgery Begins

Some patients have a separate consultation before their Mohs surgery, while others may already have discussed the procedure with their dermatologist. Before treatment, your team will review your general health, medicines, allergies, aftercare needs and any questions or concerns you have.

When you arrive for surgery, the surgeon will examine the skin cancer and normally mark the treatment area. A clinical photograph may also be taken as part of your confidential medical record.

Most Mohs procedures use local anaesthetic, so you remain awake while the treatment area is numbed. The injection may sting briefly, but the area should then become numb before the surgeon starts removing tissue.

Unless your medical team has given different instructions, you can generally eat and drink on the day. It is also sensible to wear comfortable clothes, bring an up-to-date medication and allergy list, and take something to read or watch during the waiting periods.

The Cancer Is Removed in Stages

During the first stage of Mohs surgery, the surgeon removes the visible tumour together with a thin layer of surrounding tissue. A temporary dressing is then placed over the wound while the removed tissue is processed and examined under a microscope.

This laboratory examination is an important part of the procedure. It allows the surgeon to see whether cancer cells remain at any of the edges of the removed tissue.

If the margins are clear, no further cancer needs to be removed. If cells remain, the surgeon uses the tissue map to remove another thin layer only from the area where cancer is still present. The process continues until the margins are clear.

Around 90% of skin cancers treated with Mohs are cleared within one or two stages, although some require additional stages.

Expect Plenty of Waiting Time

One of the biggest surprises during a first Mohs surgery appointment is that much of the day may involve waiting rather than undergoing surgery.

The microscopic analysis between stages can take considerable time. British Association of Dermatologists guidance says results can take up to three hours, while Dr Arif Aslam's patient guidance notes that processing and examination often take around an hour for each stage.

Overall, Mohs takes around half a day on average, although complex cases can require most or all of the day. Dr Arif Aslam's guidance gives an average procedure length of approximately two to four hours, with longer appointments possible when several stages are required.

For that reason, avoid scheduling work, appointments or important commitments afterwards. Bring a book, phone, tablet or another quiet activity to make the waiting periods easier.

What Happens After the Cancer Is Clear?

Once the surgeon confirms that all cancer has been removed, attention turns to repairing the wound. The final size of the wound is not always predictable beforehand because the cancer may extend further beneath the skin than is visible on the surface.

Depending on the size and location, the wound may be closed with stitches, repaired using a skin graft or local flap, or allowed to heal naturally under a dressing. In some cases, another specialist surgical team may perform the reconstruction.

Before you leave, the clinical team should explain how to look after your dressing and wound, manage discomfort and recognise signs that require medical advice. Follow-up may also be arranged for wound checks, dressing changes or stitch removal.

You should plan your journey home beforehand. Current British Association of Dermatologists guidance advises patients not to drive or use public transport following Mohs surgery, while individual clinic instructions may vary according to the location of the operation and whether sedation has been used.

Feel Prepared for Your First Appointment

Your first Mohs surgery appointment will usually involve local anaesthetic, removal of the cancer in stages, periods of waiting while tissue is examined and reconstruction once the margins are clear. The process can take several hours, but the staged approach allows the surgeon to check the cancer margins while preserving as much unaffected skin as possible.

If you are preparing for Mohs surgery, keep the day free, bring anything your clinic has requested and make sure you understand your transport arrangements. Contact Dr Arif Aslam's team if you would like personalised guidance about your upcoming appointment, reconstruction options or recovery.