What is a biopsy?

A biopsy is the removal of a sample of tissue from the body for examination. The tissue will be examined under a microscope to assist in diagnosis. Therefore, only very small samples are needed.

Sometimes, it is enough just to scrape over an area. This is the case with cell examinations of the cervix (neck of the womb).

During examination of the large intestine, a biopsy can be taken with forceps through a tube known as an endoscope.

In other cases, for instance, a liver or kidney biopsy, the biopsy is taken using a large hypodermic needle.

Liver biopsy

A liver biopsy can be used to confirm diagnoses such as hepatitis, cirrhosis of the liver or tumours.

The biopsy is usually performed with the patient lying on their left side with their right shoulder extended and their right hand under their head. It is important to remain in this position and to keep as still as possible. A local anaesthetic will be given to numb the skin.

A needle is then guided between two ribs towards the surface of the liver, and the biopsy taken very quickly.

Endometrial biopsy

This biopsy is taken in order to examine the lining of the womb.

If a woman is suffering from irregular periods or abnormal vaginal bleeding, it may reveal a hormone imbalance in the body, polyp formation or, less commonly, the development of a tumour.

An endometrial biopsy can be performed in a number of different ways.

Dilatation and curettage (D&C)

(D&C) is a common gynaecological procedure but is being replaced by the more modern practice of hysteroscopy.

A D&C is performed under a short general anaesthetic. The cervix is opened gradually by introducing a series of rounded sticks or dilators. These are initially very small but increase in size until the cervix is dilated sufficiently to accept a curette - a small instrument shaped like a rectangular spoon. The curette is used to obtain a sample from the lining of the womb.

Hysteroscopy

A fibre-optic tube with a bright light at the end is inserted through the cervix to obtain a direct view of the lining of the womb. Biopsy under direct vision can be made by passing forceps through the inside of the tube into the womb. This is usually performed under a local anaesthetic but some women may be advised to have a general anaesthetic.

Other methods have been developed to allow a small sample of tissue to be removed from the womb lining without anaesthetic in an outpatient clinic.

The most common is a flexible, straw-like device with a plunger. This allows the gynaecologist to apply gentle suction to the lining of the womb and obtain a sample or biopsy of tissue.

Prostate biopsy

A prostate biopsy may be performed if abnormality is found by the doctor or nurse while performing a digital rectum examination (DRE).

A trans-rectal ultrasound scan (TRUSS) of the prostate gland may be requested to assess any abnormality felt on DRE, or if a blood test shows an elevated PSA (prostate specific antigen) blood test.

The procedure takes place in hospital and is performed without anaesthetic.

The radiologist or urologist performing the procedure will have requested any patients taking blood thinning agents, eg aspirin or warfarin, to have discontinued them for up to one week beforehand because of the risk of bleeding. Antibiotics will be given to the patient beforehand to cover the risk of infection.

Throughout the biopsy, the patient lies on his side with his knees bent and his legs pulled up to his chest.

If any abnormality is seen on the ultrasound scan, a biopsy is taken quickly. The patient feels a short, sharp shock as a number of small needles move in and out of the prostate.

The procedure can also be done without ultrasound guidance. To do this the doctor uses a finger to guide a single needle to the abnormal area and takes a series of biopsies, one after the other.

After the procedure the patient may experience some discomfort for a short period of time and possibly notice some blood in their urine intermittently for a few days.

Skin biopsy

When there are changes in the skin that require further examination, a skin biopsy may be useful. First, a local anaesthetic is given, then a small piece of skin is cut off with a scalpel. Then the skin is sewn together again with a couple of stitches. This leaves a very small, almost invisible, scar.

Bone marrow biopsy

A bone marrow biopsy may be necessary for many different diseases of the bone marrow, the blood and the lymphatic system. The biopsy will normally be taken from the upper part of the hip (a point called the iliac crest), but it can also be taken from the breastbone.

First, a local anaesthetic is given. Then a strong needle is led through the skin and the outer part of the bone until it reaches the softer, central part of the bone (bone marrow). A syringe is put on the loose end of the needle and some bone marrow is sucked out. This sample is examined under a microscope.

Breast biopsy

This kind of biopsy is used if a clinical examination, ultrasound scan or a mammography reveals the possibility of a lump or tumour in the breast. The biopsy determines whether the lump is benign or malignant.

One method called fine-needle aspiration or FNA, uses a hypodermic needle to pierce the skin and suck out the sample. This may sometimes be done under ultrasound or X-ray guidance.

Another option is a surgical biopsy, where the whole lump is removed.

Small intestine biopsy

It is not always possible to examine the central part of the small intestine (jejunum) with an endoscope. In such cases, a biopsy capsule is used to take samples from the area.

The patient swallows the capsule, which is connected to a thin tube. Then, an X-ray is taken to make sure that the capsule is in the jejunum. When the capsule is in the right place, a partial pressure is created in the tube by pulling back a syringe connected to the other end of the tube. In this way, a small piece of the mucous membrane of the small intestine is sucked into the capsule. The membrane sample is cut off in the capsule, and the capsule is pulled back so that the biopsy can be examined. This is most useful in the investigation of the bowel condition called coeliac disease.