There are several stages to Mohs’ surgery. First, your 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. If you are particularly anxious, we can give you a mild sedative to help you relax. Please discuss this with the doctor. We may also use anaesthetic eye drops if your tumour is near your eye.
Once the anaesthetic has taken effect, the visible (also called the clinically evident) part of the tumour will be removed, along with a small 1-2mm margin of normal skin. The tissue will then be processed and prepared so that your surgeon will be able to look at it under a microscope to check for cancer cells. This takes about 60-75 minutes. A temporary dressing will be applied to your wound and you will be asked to sit in the waiting area.
If cancer cells are present in this tissue, you will be brought back into theatre for more tissue to be cut out and examined under the microscope. This will be repeated until all the tumour cells have been removed.
The local anaesthetic lasts for about 2 hours, and can be ‘topped up’ if needed. Because of the nature of this surgery, we are unable to tell you exactly how long your surgery will last.