What causes micrographic surgery?
This is a specialised form of surgery to remove certain skin cancers and is also called Mohs’ surgery after the doctor who developed it. The surgeon removes the visible portion of your tumour and then removes further tissue that may have cancer cells, one layer at a time. This tissue is examined under a microscope while the patient is still in the dermatology unit. If it contains cancer cells, another layer of tissue is removed and examined. This is repeated until all the cancer cells have been removed.
This technique is most suitable for tumours in anatomic areas associated with a high risk of recurrence such as the head, neck, eyes, lips, nose and ears, recurrent or persistent tumours, morpheic BCC, neutrophic spread or perineural invasion, Gorlin’s syndrome, multiple SCC’s in the immunocompromised and tumours arising in areas previously treated with radiotherapy.
Your doctor may have recommended Mohs’ surgery because:
- The skin cancer has returned;
- The tumour was previously removed, but some cancer cells remain;
- The cancer is in an area where we want to reduce the amount of healthy tissue removed, such as the eyelids, nose, ears or lips
- The edges of your tumour are not well defined or if the skin cancer may be of the aggresive type.
Why should I have micrographic surgery?
Other types of surgery for skin tumours rely on the surgeon being able to see the extent of the cancer, which can either lead to a large wound and scar if too much healthy tissue is removed or too little tissue being removed and the cancer returning. Micrographic surgery maximises the chances that the tumour will be completely excised (removed) while minimizing the amount of surrounding normal skin needed to be taken away.
What happens during Mohs’ surgery?
There are several stages to Mohs’ surgery. First, the doctor will inject the area where your tumour is, with a local anaesthetic. This numbs the area, so you will not feel any pain during surgery. It will not put you to sleep, so you will remain awake throughout the surgery. Once the anaesthetic has taken effect, the visible part of the tumour is removed, along with a small margin of normal skin tissue. This tissue is taken to a laboratory where your doctor will be able to look at it under a microscope to check for cancer cells. This takes about 40-60 minutes, so a temporary dressing is applied to your wound and you are asked to sit in the waiting area. If cancer cells are present in this tissue, you will be brought back into theatre and more tissue will be taken away and examined under the microscope. This will be repeated until all the tumour cells have been removed.
What happens after the procedure?
Once all the tumour cells have been removed, there are several options for repairing your resulting wound.
The wound may be:
- Closed by the team who performed the micrographic surgery immediately after the tumour has been removed;
- Dressed and then repaired by a plastic surgeon at a hospital chosen by our surgeon;
- Left to heal normally; or
- Repaired at another hospital.
The advantage of this form of surgery is it achieves the best cure rates (99% in primary tumours, 95% in recurrent tumours), as well as, lowest recurrence rate with maximal preservation of uninvolved tissue, allowing the best healing outcome and aesthetic repair, for most skin cancers.