Micrographic surgery (MOHs) is a highly specialised and effective surgical technique available for the removal of skin cancers.

The principles behind it were developed by Dr Frederic Mohs in the 1930’s at the University of Wisconsin. The procedure over the years has been modernised and refined and is now practiced all over the world.

All doctors at the Ballarat Surgicentre have undergone extra training to become skilled experts in performing Mohs procedures. They are Australasian College of Dermatologists (ACD) Approved MOHS Micrographic Surgeons. 

MOHs surgery has the highest reported cure rate (99% for skin cancers that have had no prior treatment) and ensures that the smallest amount of healthy skin around the tumour is removed.

MOHs surgery produces a small defect (wound) for repair in comparison to standard surgery.

It is usually undertaken as a single day procedure under local anaesthesia and allows the immediate and complete microscopic examination of the removed cancerous tissue.

The surgery is performed by our dermatologists by removing the cancerous tumour layer by layer. There are several steps that are undertaken, these are as follows:

1. The visible tumour plus a margin is outlined using a skin marker, and a reference map or grid is drawn on the patient.

2. The area is excised at an angle of 30-45 degrees at the radial margins.

3. Haemostasis is obtained and the wound is temporarily dressed.

4. The excised tissue sample is divided into two or more sections that are stained using special tissue dyes.

5. A mapping process ensures that residual tumour seen under the microscope can later be matched to the exact location on the patient.

6.  A specialised Mohs Scientist embeds and freezes the tissue in a cryostat to create horizontal sections of the entire excision margin.

7. The Mohs Surgeon examines the microscopic sections for remaining cancer. 

8. Any remaining cancer is precisely drawn on the map

9. This map is then used to identify the area on the patient from which more tissue needs to be removed.

10. The process is repeated until the patient is tumour free.

11.The wound is closed.

** Steps provided as a courtesy of DermNet NZ
Patients that are booked in for Mohs surgery, will be provided with detailed information about the surgery and what to expect. The time taken for the Mohs procedure will vary and depend on the number of stages required to achieve clearance of the tumour.