Diagnosis and investigations

A biopsy is a medical procedure that involves taking a small sample of body tissue so it can be examined under a microscope.

A tissue sample can be taken from almost anywhere on or in your body, including the skin, organs and other structures.

The term ‘biopsy’ is often used to refer to both the act of taking the sample and the tissue sample itself.

When a biopsy may be needed

A biopsy can be used to investigate abnormalities.

When the tissue sample is examined under the microscope, abnormal cells may be identified. This can help to diagnose a specific condition.

If a condition has already been diagnosed, a biopsy can also be used to assess its severity (such as the degree of inflammation) and grade (such as the aggressiveness of a cancer). This information can be very useful for:

• deciding on the most appropriate treatment
• assessing how well a person responds to a particular type of treatment
• helping to determine a person’s overall prognosis (outlook)

It’s not usually possible to tell whether a lump or growth on your skin or inside your body is cancerous (malignant) or non-cancerous (benign) by clinical examination alone, which is why a biopsy is often required.

Types of biopsy

There are many ways of getting a tissue sample. It depends on the type of tissue being collected and where in the body it’s being taken from.

Imaging techniques, such as X-ray, ultrasound, CT scanning, Mamogram or MRI scanning is often used to guide many types of biopsy.

A number of blood tests can be carried out to help diagnose certain cancers or check if you’re at an increased risk of developing a particular type of cancer.

These include tests for:

• prostate-specific antigen (PSA) – this can help diagnose prostate cancer, although it can also detect other problems such as an enlarged prostate or prostatitis
• CA125 protein – a protein called CA125 can indicate ovarian cancer, although it can also be a sign of other things such as pregnancy or pelvic inflammatory disease (PID)
• BRCA1 and BRCA2 genes – certain versions of these genes can greatly increase a woman’s chance of developing breast cancer and ovarian cancer; this test may be carried out if these types of cancer run in your family

A computerised tomography (CT) scan uses X-rays and a computer to create detailed images of the inside of the body.

CT scans are sometimes referred to as CAT scans or computed tomography scans.

They’re carried out in hospital by specially trained operators called radiographers and can be done while you’re staying in hospital or during a short visit.

When CT scans are used

CT scans can produce detailed images of many structures inside the body, including the:

• internal organs
• blood vessels
• bones

They can be used to:

• diagnose conditions – including damage to bones, injuries to internal organs, problems with blood flow, strokes and cancer
• guide further tests or treatments – for example, CT scans can help to determine the location, size and shape of a tumour before having radiotherapy, or allow a doctor to take a needle biopsy (where a small tissue sample is removed using a needle) or drain an abscess
• monitor conditions – including checking the size of tumours during and after cancer treatment

CT scans wouldn’t normally be used to check for problems if you don’t have any symptoms (known as screening). This is because the benefits of screening may not outweigh the risks, particularly if it leads to unnecessary testing and anxiety.

About an MRI scan

Magnetic resonance imaging (MRI) is a type of scan that uses strong magnetic fields and radio waves to produce detailed images of the inside of the body.

An MRI scanner is a large tube that contains powerful magnets. You lie inside the tube during the scan.

An MRI scan can be used to examine any part of the body.

The results of an MRI scan can be used to:

• help diagnose conditions
• plan treatments
• assess how effective previous treatment has been

Positron emission tomography (PET) scans are used to produce detailed three-dimensional images of the inside of the body.

The images can clearly show the part of the body being investigated, including any abnormal areas, and can highlight how well certain functions of the body are working.

PET scans are often combined with computerised tomography (CT) scans to produce even more detailed images. This is known as a PET-CT scan.

They may also occasionally be combined with a magnetic resonance imaging (MRI) scan. This is known as a PET-MRI scan.

An X-ray is a quick and painless procedure commonly used to produce images of the inside of the body.

It’s a very effective way of looking at the bones and can be used to help detect a range of conditions.

X-rays are usually carried out in hospital X-ray departments by trained specialists called radiographers, although they can also be done by other healthcare professionals, such as dentists.

How X-rays work

X-rays are a type of radiation that can pass through the body. They can’t be seen by the naked eye and you can’t feel them.

As they pass through the body, the energy from X-rays is absorbed at different rates by different parts of the body. A detector on the other side of the body picks up the X-rays after they’ve passed through and turns them into an image.

Dense parts of your body that X-rays find it more difficult to pass through, such as bone, show up as clear white areas on the image. Softer parts that X-rays can pass through more easily, such as your heart and lungs, show up as darker areas.