Fine needle biopsy at Woking Hospital

What is a fine needle biopsy?

A fine needle biopsy draws out a tiny sample, either cells or a little fluid, from a lump or unusual patch in your body, using a slim needle attached to a syringe. A specialist then studies this sample under a microscope to work out what's causing it.

Why might I need a fine needle biopsy?

Your consultant might suggest this test if you, or a scan, have picked up a lump, swelling or unusual area somewhere in your body. It's a common next step for lumps in the breast or thyroid, or swollen glands in the neck, though it can be used almost anywhere.

Sampling the area this way can help work out whether what's there is:

• a harmless fluid-filled cyst
• an infection, and if so, which germs are responsible
• a non-cancerous growth, such as a lipoma
• a cancerous change that needs further treatment.

Occasionally, the same needle is used to drain fluid from a cyst or a collection of pus, easing symptoms at the same time as collecting a sample.

What are the benefits of a fine needle biopsy?

Because the needle involved is so fine, this test lets your doctor look inside a lump without the cutting, stitches or lengthy healing time that surgery would involve. Many people are in and out within an outpatient visit, with little disruption to their day.

Getting a sample this way often settles the question quickly, so treatment, if any is needed, can start sooner rather than waiting on a more invasive procedure.

Are there different types of needle biopsy?

A fine needle biopsy uses the thinnest kind of needle, drawing out individual cells rather than a solid piece of tissue.

A core biopsy, by comparison, uses a wider hollow needle to take out a small column of solid tissue, which can offer more detail but sometimes calls for a small cut in the skin first.

Which one you have also depends on where the lump sits. If it can be felt through the skin, your doctor may sample it directly. If it's deeper or harder to pinpoint, they'll use a scan, such as an ultrasound or CT, to guide the needle precisely to the right spot.

Do I need a referral for a fine needle biopsy?

Yes. This test is arranged through your consultant or doctor, usually after they've found something worth investigating during an examination or on a scan. They'll explain their reasons for suggesting it before you attend, and a radiologist or other trained specialist carries out the procedure itself.

How do I prepare for a fine needle biopsy?

There's usually very little to do beforehand. You can eat and drink as normal in most cases, since fasting is generally only needed if you're having sedation.

A few practical things are worth arranging in advance:

• Let your team know about any medicines you take, particularly blood thinners, as they may need adjusting beforehand
• Bring a small snack with you if you're diabetic, in case your sugar levels need topping up afterwards
• Organise a lift home beforehand if you'd rather not drive yourself afterwards
• Be ready to change into a gown provided by the hospital, if the area being tested calls for it.

What happens during a fine needle biopsy?

The exact experience varies by body area, but the general pattern is similar throughout:

1. You'll sit or lie down, and the skin over the area is cleaned
2. A local anaesthetic may be injected first to numb the area, though the needle itself is often thin enough that this isn't always necessary
3. If the lump can't easily be felt by hand, your doctor uses ultrasound or another scan to guide the needle to the right spot
4. The needle is inserted, and a syringe gently draws out a small amount of tissue or fluid – you may feel a brief pinch or some pressure
5. This may be repeated a few times, or with a fresh needle, if more than one sample or area needs testing
6. Once enough has been collected, the needle is withdrawn and a small dressing is placed over the area.

What happens after a fine needle biopsy?

The sample travels on to a lab, where a specialist studies it down a microscope and writes up a report for your doctor to go through with you.

Most people go home the same day, with nothing more needed than a plaster or small dressing over the area. It's sensible to take it easy for the rest of the day, and a little soreness or bruising at the site is normal, usually settling within a day or two.

Results can sometimes come back within days, though a fuller report may take up to a week or so, depending on what further tests the sample needs.

Occasionally, the sample doesn't contain quite enough cells for a clear answer, in which case your doctor may suggest repeating the test; this isn't a sign that anything was done wrong the first time.

What are the risks of a fine needle biopsy?

This is a low-risk test overall. The most common issues are minor bruising or bleeding where the needle went in, which typically settles on its own within a day or two.

Less commonly, there's a small chance of:

• infection at the site
• ongoing bleeding, particularly if you take blood-thinning medicine or have a clotting condition
• injury to structures near the area being sampled
• an abnormal connection forming between two tissues (a fistula), which is rare.

Contact your doctor if you notice a fever, pain that's getting worse or not easing with painkillers, spreading redness or warmth, swelling, fluid leaking from the site, or bleeding that pressure alone won't settle.