Re-excision – sometimes called wide excision – is a surgical procedure that follows an initial biopsy used to determine whether a mole or lesion is cancerous. Only if the biopsy is determined to be cancerous is the re-excision procedure required. With a re-excision, the skin around the site of the lesion or tumour is removed. This is to maximise the chance that all of the cancerous cells have been removed. The amount of seemingly healthy tissue removed depends on the size and depth of the original lesion. The larger and deeper the lesion, the more skin has to be removed at the re-excision stage.
The following may be used as a guide for re-excision margins (the amount of additional skin to be removed):
- 5mm for in situ melanoma
- 1cm for melanoma up to 2cm wide
- 2cm for melanoma over 2cm wide
- 5cm for Dermoplastic Melanoma (a type of melanoma with a high recurrence rate)
It is important that any re-excision is down to the muscle.
Where the amount of skin that must be removed is too large for the scar to be simply sewn together – a 'flap repair' may be necessary. With this procedure, a piece of adjacent skin is moved and used to cover the area where the lesion was removed (unlike a normal skin graft where skin is removed completely from one area of the body and transposed to another).
The flap of skin is not fully removed from the body, but moved over the area where the margin skin was removed. This preserves the colour and look of the skin and enables the wound to recover more quickly, as the blood supply remains intact. There are different types of flap repairs, referred to as 'rotation flaps', ‘transposition flaps' or 'advancement flaps'.
In cases where a flap is not recommended a skin graft may be required to repair the deficit from the wide local excision. This is where skin is taken from a different area of the body to cover the deficit left from the removal of the cancer and additional skin.