Mohs surgery is a highly specialised treatment for the removal of skin cancers in which a microscope is used to determine the extent and depth of the skin cancer. The removal of the skin cancer is performed by a dermatologist with specific training in this technique. Once the skin cancer is removed, the area is repaired by A/Prof Wilcsek.
Whenever a skin cancer is removed a "border" of normal tissue is taken in an effort to ensure complete tumour removal. Moh’s surgery is a technique to microscopically “map” the extent of the skin cancer, therefore this border of normal tissue neighbouring the skin cancer can be kept to a minimum. This can result in a smaller area of tissue loss and so potentially a simpler reconstruction is required.
When is Mohs Surgery chosen for removal of a skin cancer?
What does the treatment involve?
The area of skin suspicious for cancer is treated with local anaesthetic. A thin piece of tissue is removed and carefully divided into pieces that will fit on a microscope slide. The edges are then marked with specially coloured dyes and a careful map of the tissue removed is made. The tissue is frozen and thin slices are made and placed on glass slides to be examined under the microscope.
The doctor will examine the slides under the microscope to check if there is any tumour present. If cancer cells remain, another layer of tissue is then surgically removed and the procedure is repeated until no cancer cells remain. This process preserves as much normal, healthy surrounding skin as possible.
The removal of each layer of tissue takes approximately one hour. Only 20 - 30 minutes of that time is spent in the actual surgical procedure, the remaining time being required for slide preparation and interpretation. It may take the removal of two or three layers of tissue to complete the surgery. In between procedures the wound is dressed whilst the patient is asked to wait.
When the Moh's surgery is complete, A/Prof Wilcsek will reconstruct the area. The reconstruction techniques required will vary depending on the amount and site of tissue that has been removed.
How will I look immediately after surgery?
What is the recovery time?
What are the risks?
Is there a risk of the cancer returning?
By checking the margins of excision (edges of the specimen taken) by Mohs or frozen section the recurrence rate is made as low as possible. Skin cancers develop in areas of sun damage and these areas are also prone to developing new skin cancers. The area involved needs to be monitored and A/Prof Wilcsek does this in the postoperative period but follow-up with your referring doctor is very important to monitor for any recurrence, or onset of new skin cancers in the area.
Using this technique the percentage of curing is very high, often 97% - 99%, even if other forms of treatment have failed. However, no one can guarantee a 100% cure and therefore a follow-up period of 5 years is advised.