Mohs: How is the Procedure Performed?

The sequence of events was depicted in FIGURE 2 of "What is Mohs Surgery" the basics of the method are pictured in FIGURE 3:

1-­ 4 Following local anaesthesia, the lesion is debulked with a curette. A 2 ­ 3mm margin of normal appearing skin is outlined around the remaining tumour as it appears on the skin surface. The lesion is surgically removed, producing a saucer-shaped specimen. This shape is critical to the later preparation of a complete survey of the excision margins, which cannot be achieved by any other method.

The removed tissue is then divided into segments and colour-coded to orientate each specimen and marked on a detailed diagram.

5- 6 The tissue is frozen on a cryostat. The under-surface and all edges of each section are then microscopically examined for evidence of remaining cancer.

7 If any microscopic roots of the cancer are present, the residual tumour is located by way of the map, which then allows for removal from any area in which tumour still persists.

8-­ 9 This process continues in a layer-by-layer fashion until microscopically controlled tumour extirpation has occurred.

Reconstruction can then be performed immediately or as a planned procedure.