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Surgical Removal of Rodent Ulcers

There are several ways to treat rodent ulcers, but current evidence suggests that most types of rodent ulcer are best treated by surgical removal, particularly those on the face, head and neck. This usually gives the best cosmetic result and the best chance of a complete cure.


It is always important to remember that a rodent ulcer is a destructive skin cancer. Any treatment cannot make you look as though nothing has happened, and the results of treatment need to be considered and weighed against the consequences of leaving a tumour to destroy the surrounding area.

What does surgical removal involve?
Most patients can have this done under local anaesthetic, that is, while they are awake. An injection in the skin makes the skin numb. A numbing cream can be used before the appointment to make the injection less uncomfortable. More extensive surgery sometimes requires the use of intravenous sedation (a twilight sleep), especially for nervous patients, or occasionally by using a general anaesthetic (being completely asleep).

Step 1
The edge of the rodent ulcer is marked with a special pen and a surrounding rim of skin usually 4-5mm wide of normal looking tissue is also marked to help ensure that the rodent ulcer is completely removed. Rodent ulcers usually have invisible cells in the skin that extend beyond the area which can be seen, and evidence suggests that removal of this extra rim of skin along
with the tumour ensures complete clearance of all the cancer cells in over 95% of cases.

A tumour marked before removal

Step 2


Local anaesthetic is injected with a needle and the area is checked for numbness. The rodent ulcer and its cuff of normal tissue around the edges and underneath is removed and put in a special container, which is then sent to the pathologist to be examined under the microscope. The speciment is marked with a stitch to show which way round it sat on the skin. The pathologist checks to see if the skin lesion is what we thought it was and that it has been completely removed. The pathology report often takes around 10 days, but may take longer if further tests are needed.


The pathologist with whom Professor Newlands works most closely is Dr Balamarugam, expert skin cancer histopathologist to the Regional Skin Cancer MDT.

A defect after removal

Questions about the surgery


What happens to the gap which is left in the skin?

In most cases, the gap which results is closed by reconstruction at the same time as removal of the tumour. Sometimes, if the tumour is indistinct or recurrent and there is a possibility of the margins not being clear, reconstruction is delayed until this is confirmed.


This can either be by Mohs surgery or by excision with delayed repair, where conventional excisional surgery is undertaken, the edges are looked at by a pathologist, and reconstruction is undertaken around a week later, once clearance is confirmed.

Nose flap to close a BCC defect once confirmed complete removal at previous surgery

If the gap is small and there is plenty of spare skin around, then the skin can be brought together with stitches. There will then be a line of stitches which will be blended into the natural lines of the area. This line will be longer than the original rodent ulcer, because a cuff of normal skin has also been removed. It is usually necessary to take a couple of darts in the skin to stop the area becoming puckered. Dissolving stitches under the skin are commonly used, and the top layer is then closed with removable or dissolving stitches, depending upon the site of surgery and the type of skin.

The direct excision procedure:

1. before excision (note the darts positioned in a natural skin crease)

2. after excision

3. after suturing

On the face, moving the skin together can sometimes risk distorting features, such as causing the eyelid to be pulled down. To help avoid this, it is often necessary to borrow some looser skin from somewhere else. This can be adjacent skin, which has more laxity or give. Some nearby skin is partly detached and swung into the gap, but stays joined to its blood supply. This is called a local flap. The site from which a local flap is chosen depends upon where there is spare skin, and the shape and position of this is chosen to minimise any distortion, and to hide the scars in natural skin creases where possible.

Local flap in cheek put into place, and final result

1. roduct ulcer and area for flap marked

3. cheek after flap closed

2. roduct ulcer excised and flap prepared

4. cheek after healing

Sometimes there is not enough skin in the local area and a skin graft is needed. In this case, a piece of skin is detached from somewhere where skin is spare. This is commonly in front of the ear (which has the advantage of giving a 'mini-facelift'!), or from the lower neck near the collar bone. The area where the skin graft has been taken from is loose enough to sew back together again. The skin graft is then joined onto the gap resulting from removal of the skin tumour and covered with a dressing for several days. Sometimes skin grafts can be used which have hair-bearing skin present and this can be useful if an area such as an eyebrow needs to be reconstructed.

Graft placed in ear, and final result

1. rodent ulcer to be removed marked; graft is marked

3. graft inserted and donor site closed

2. graft itaken and excised area prepared

4. donor site cand graft after healing

What happens if the microscope test shows the tumour is not completely removed?
Incomplete excision of a rodent ulcer is uncommon if you are treated by a surgeon with a lot of experience.

Further surgery is not always required. Sometimes the area can be watched, as many incompletely-excised, low-risk BCCs will not come back. Sometimes re-excision is advised, or Mohs surgery, or radiotherapy or application of a special cream. Close or incomplete excisions are discussed at the Skin Multidisciplinary Team, and recommendations made to discuss with the patient. Orientation of the specimen at the time of surgery means that an area where the margin was close or involved can be identified in the scar.

Professor Newlands' audited BCC complete excision rate of over 5000 lesions treated in the years 2003 to 2023 is more than 98%.

What are the possible side-effects and risks of surgery?
When a local flap is used, the repair can sometimes be lumpy for a while until the tissue fluid settles. Rarely, further minimal surgery can help. This is usually carried out some months after the original procedure to let nature do its best.

Skin grafts can occasionally dislike being moved and an audit of our work has shown a very high take rate. Even so, around 1 in 40 skin grafts fail to establish themselves in the new position. In this case, further grafting is not usually necessary, but the area may take some time to heal and need frequent dressings. A skin graft which does 'take' can often be slightly redder to begin with, but can end up paler than the surrounding skin. Because the skin graft is often not as thick as the slice of tissue that was removed, there can sometimes be a dip or a hollow in the region where the skin graft has taken.

It is not possible to perform surgery without creating scars, but with artistry and good needlework, most patients end up with a great result. It is always important to remember that scars take a long time to settle, and that leaving a skin cancer left without treatment will often result in greater disfigurement.

Skin lesions information leaflet [.pdf]

See start-to-finish images of treatments and their post-operative results

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