Excisional biopsy at Cheltenham Hospital

What is an excisional biopsy?

An excisional biopsy is a small operation to remove a lump or an abnormal area of skin completely, along with a thin border of healthy tissue around it. The tissue is then sent to a laboratory, where a specialist called a pathologist looks at it under a microscope to find out what it is.

Why might I need an excisional biopsy?

You might be offered an excisional biopsy if:

• a lump, mole or patch of skin looks unusual on examination or on a scan and needs to be looked at fully
• an earlier needle or core biopsy did not give a clear answer
• your specialist suspects melanoma, a type of skin cancer, and needs to check how deep it goes
• a lump is uncomfortable, gets knocked often, or keeps becoming infected
• you want a non-cancerous growth or a skin cancer removed.

What are the benefits of having an excisional biopsy?

Because the whole lump is removed rather than just a small sample, the pathologist can look at its entire structure and edges. This gives a fuller picture than a partial sample and lowers the chance of a missed or unclear diagnosis.

For a small, self-contained lump, the biopsy can also treat the problem at the same time as diagnosing it, since removing it completely may be all the treatment you need. If melanoma is suspected, the test also shows how deep it has grown, which helps your specialist plan any further care.

How do I prepare for an excisional biopsy?

Preparation is usually straightforward and depends on the type of anaesthetic you're having:

• If you're having local anaesthetic (numbing medicine) only, you can usually eat and drink as normal beforehand
• If you need sedation or a general anaesthetic, you'll be asked to fast (avoid food and drink) for a set time before, often 6 to 8 hours
• If you take blood thinners or aspirin, your doctor may ask you to stop these for a few days beforehand
• You'll be asked to sign a consent form once your doctor has explained the procedure

What happens during an excisional biopsy?

1. You'll change into a gown, or the area to be biopsied will be uncovered
2. Your doctor marks the area of skin to be removed and talks you through each step
3. You lie down, and a local anaesthetic is injected to numb the area – this may sting briefly, but the area then goes numb, so you shouldn't feel pain, though you may notice gentle pressure or pulling
4. Your doctor cuts out the whole lump, plus a small margin of healthy skin around it, using a surgical knife (scalpel)
5. An X-ray or ultrasound scan may be used during the procedure to help find the exact area, if needed
6. The wound is closed, usually with stitches, and covered with a dressing
7. The tissue removed is sent to a laboratory, where a pathologist examines it under a microscope.

The whole procedure usually takes between 15 minutes and 1 hour, depending on the size and place of the lump.

What happens after an excisional biopsy?

If you had sedation, you'll need to rest for an hour or two afterwards, and you'll need someone to take you home, as you will not be able to drive. If you only had local anaesthetic, you can usually go home soon after, once your doctor has checked the wound.

As the numbing medicine wears off, it's normal to have some discomfort and light bleeding where the biopsy was taken.

A small pocket of blood (a haematoma) can also form under the skin. This can be uncomfortable but usually improves over the next few days, and paracetamol can help with any pain. It's best to avoid aspirin, as this can increase bleeding.

Most people recover within 1 to 2 weeks. You'll usually be able to return to light daily activities or office work within a few days, but should avoid strenuous activity, heavy lifting and sport until your stitches are removed or your doctor says it's safe.

Keep the dressing dry for 5 to 7 days, and follow the advice you're given on caring for the wound and watching for signs of infection.

Stitches that dissolve on their own usually go within 2 to 4 weeks. Stitches that need removing are usually taken out after 1 to 2 weeks, though this can range from 5 to 14 days depending on where they are.

Your doctor will discuss the results with you at a follow-up appointment once the pathologist's report is ready.

What are the risks of an excisional biopsy?

• Bleeding: A little light bleeding or oozing is common straight after the biopsy – if bleeding continues, apply firm pressure with a clean cloth for 15 minutes and contact your doctor if it doesn't stop
• Haematoma: A build-up of blood under the skin, which can be uncomfortable but usually settles on its own
• Infection: Shown by redness, pain, swelling, warmth or discharge from the wound. Contact your doctor if you notice these signs
• Scarring: The wound will leave a scar, and how it looks depends on the site and size of the area removed
• Swelling and bruising: These are common and usually settle within a few days
• Nerve damage: Rare, and more likely if the biopsy is close to a nerve.