A biopsy is a way of diagnosing diseases. A doctor removes a sample of tissue or cells to be examined by a pathologist, usually under a microscope.
A pathologist is a specialist who is trained to examine a sample of tissue for signs and extent of disease under a microscope.
Tissue for a biopsy is normally taken from a living subject.
The word biopsy comes from the Greek words "bios," meaning "life," and "opsis," meaning "a sight." Together, they mean "to view life."
Depending on the aim, a biopsy may be excisional or incisional:
- An excisional biopsy is when a whole lump or targeted area is surgically removed
- An incisional biopsy, or core biopsy, involves taking a sample of tissue
There are different types of biopsy.
A scrape: Cells are removed from the surface of tissue, for example, from the inside of the mouth or the neck of the womb, or cervix. It is often used in cervical cancer screening, commonly known as pap smears. It can be used to confirm fungal infections of the skin.
A punch biopsy: A punch is a round-shaped knife that is used to cut and remove a disk of tissue. This is used to collect a sample of skin tissue to check for malignancy, or cancer It can also be used to check for inflammation.
A needle biopsy: A needle is used to remove a sample, usually of liquid. A wide needle is used for a core biopsy, while a thin one is used for a fine-needle aspiration biopsy (FNAB). It is often used for breast and thyroid sampling.
A capsule biopsy: This is used to take a sample from the intestines.
Stereotactic biopsy: Samples are taken from the brain, using stereotactic surgery to find the biopsy site. A stereotactic system uses three-dimensional coordinates to locate small targets inside the body.
Colposcopic biopsy: This is used to evaluate a patient who has had an abnormal pap, or cervical, smear. The colposcope is a close-focusing telescope that allows the doctor to see areas of the cervix in detail.
Endoscopic biopsy: An endoscope is used to collect the sample. An endoscope is a long, thin, lighted optical instrument used to get deep inside the body and examine or operate on organs.
Specially adapted endoscopes include a cystoscope for the bladder, a nephroscope for the kidneys, a bronchoscope for the bronchi, in the lungs, a laryngoscope for the voice box, or larynx, and an otoscope for the ear.
Almost any organ can be biopsied.
We cannot visualize the organs or tissues inside of our body, but a biopsy helps in making a diagnosis by providing a piece of tissue for examination. Biopsies are often associated with cancer, but they can be used to diagnose other conditions and to see how far a disease has progressed. They often help rule out cancer.
Conditions where a biopsy can play a role include:
- Cancer: If the patient has a lump or swelling somewhere in the body with no apparent cause, the only way to determine whether it is cancerous or not is through a biopsy.
- Peptic ulcer: A biopsy can help a doctor determine whether there is ulceration caused by non-steroidal anti-inflammatory drugs (NSAIDs). A small bowel biopsy may be used to assess patients with malabsorption, anemia, or celiac disease.
- Diagnosis of liver disease This can help the doctor diagnose tumors, or cancer, in the liver. It can be used to diagnosis cirrhosis, or liver fibrosis, when the liver is completely scarred from a previous injury or disease, such as long-term alcohol abuse or hepatitis. It can also be used to assess how well the patient is responding to treatment, for, for example, in the case of hepatitis.
- Infection: A needle biopsy can help identify whether there is an infection, and what type of organism is causing it.
- Inflammation: By examining the cells in, for example, a needle biopsy, the doctor may be able to determine what is causing the inflammation.
Sometimes, biopsies are done on transplanted organs to determine whether the body is rejecting the organ, or whether a disease that made a transplant necessary in the first place has come back.
How long it takes to get the results will depend on the type of biopsy. A straightforward result may be ready within 2 to 3 days, but a more complex case may take 7 to 10 days.
The tissue samples are sent to the lab and examined by a pathologist. They may be chemically treated and sliced up into very thin sections. They are usually studied under a microscope. A blood specialist, or hematologist, may also study the sample.
The thin slice is attached to a glass slide, and remaining tissue is usually saved for later studies.
Sometimes the slide has dyes added to it. These stain the tissue, and this helps the pathologist see the cells more clearly.
In cases of cancer, the pathologist will need to determine whether the sample is malignant, meaning cancerous, or benign. If it is malignant, they will assess how aggressive or advanced the cancer is. If it is cancer, there are special stains that can be done to help guide treatment and prognosis.
Finally, the pathologist prepares a report that includes any abnormal or important findings. This report is sent to the doctor who ordered the biopsy.
The time needed to get the results depends on the type of tests needed.
The patient will normally need to make another appointment with the doctor to receive the results. If several tests are carried out, this can prolong the turnaround time for the results.
In most cases, a biopsy is an outpatient procedure, and the patient may go home immediately or very soon after it is completed.
Preparation depends on the type of biopsy. For a fine needle biopsy that is done in the doctor's office, there will be no special preparation.
The patient will need to sign a consent form to say they agree to the procedure, and they may have to wear a gown instead of their own clothes.
In some cases, the patient should not eat or drink beforehand, and they should check with the doctor whether or not they should take their usual medications or supplements.
Sometimes, a local anesthetic will be used, with or without a medication to aid relaxation during the process.
If a sample is to be taken from an internal organ, the patient may need a general anesthetic and may have to stay in hospital overnight. Otherwise, a local anesthetic may be used.
Scraping a tissue sample from, for example, the inside of the mouth usually requires no anesthesia, but the area may feel sore for a while.
Sometimes, an incision needs to be stitched and a dressing may be necessary.
A patient who has a sample taken from a major organ, such as the liver or kidneys, may have to rest in hospital for a few hours before they can go home.
After a sample is taken from the womb lining or cervix, there may be slight vaginal bleeding.
Is it painful?
If anesthesia is used, there should be no pain during the procedure, although there will be a skin prick during the initial injection.
In a needle biopsy, a pin prick will be felt and a sharp pinch.
There may be some soreness for a few days, depending on the type of biopsy.
Is it safe?
A biopsy is usually safe, and it is considered a very low risk procedure. As with any skin perforation, there is a small chance of infection, but the risk of an infection that needs antibiotic treatment is probably lower than 1 in 1,000.
Accidental injury can occasionally affect nearby organs, for example, bowel damage during an abdominal biopsy.
Complications include the possibility of bleeding, missing the site of the suspect tissue, which can lead to a false negative result, and not collecting enough material, so that the biopsy needs repeating.
One study into the outcomes of biopsies used in clinical trials found that that 5.2 percent of such biopsies lead to complications.
A study of breast biopsies has suggested that cancer cells may break away from a lump, spreading the disease to other areas.
Whatever the risk, a biopsy can provide an early diagnosis of cancer and other diseases, and in many cases, early detection is key to increasing survival rates.