What is a needle biopsy?
A needle biopsy is a procedure that uses a thin, hollow needle and a syringe to extract cells, fluid or tissue from a suspicious lump or other abnormal area of the body. The material is then examined under a microscope or tested in the laboratory to determine the cause of the abnormality.
Why are needle biopsies done?
A needle biopsy may be called for when a doctor feels an abnormal lump or when imaging scans show the presence of abnormalities in an area of the body. Lumps of the breast, thyroid or lymph nodes are often checked using a needle biopsy.
Biopsies are frequently used to find cancer but there are also many other possible uses, including:
- Finding an infection
- Matching organ tissues before a transplant, and looking for signs of organ rejection following a transplant
- Diagnosing liver disease such as hepatitis C
- Determining the cause of bleeding in the uterus
- Determining diseases of blood vessels and connective tissue, such as muscles
- Finding nerve damage
- Finding causes of infertility
What are the different types of needle biopsies?
- Fine needle aspiration uses a thin needle several inches long and a syringe to extract cells, tissue and fluids.
- Core needle biopsy uses a wide, hollow needle to take out pieces of tissue from the area being examined.
- Stereotactic core needle biopsy uses mammogram images taken from different angles to zero in on the biopsy site. This type of test is often used when calcium deposits are present or when mammographic findings are too small to be seen with an ultrasound.
- Vacuum-assisted core biopsy uses a hollow introducer that is guided into place with imaging guidance. Tiny fragments of tissue are then suctioned into the chamber after a rotating knife cuts the sample. This method removes more tissue than a core biopsy performed with a regular needle.
How should I prepare for a needle biopsy procedure?
- Most medications can be continued before the procedure. However, patients on blood-thinning medications may be asked to temporarily halt or modify them in order to reduce possible complications from bleeding.
- Patients taking aspirin or herbal supplements should communicate this to their doctor.
- Women should report if they are pregnant, as certain imaging tests used during a needle biopsy may be harmful to the fetus.
- Although fasting is usually not required, it may be necessary in some cases to not eat or drink anything for 8 hours before the test.
- Jewelry should not be worn.
- Loose comfortable clothing should be worn.
- It may be necessary to wear a hospital gown during testing.
How is a needle biopsy performed?
- The test can be done in a doctor’s office or in a hospital as an outpatient, and normally does not take long to complete.
- The patient is usually lying down or sitting, and remains still as the test is performed.
- A disinfectant is applied in order to clean the area being tested, and a numbing agent may be used to reduce discomfort from the needle’s insertion.
- If the needle is to be inserted deeply, an imaging test such as a CT (computed tomography) scan, mammogram (for biopsies of the breast) or ultrasound may be used to guide the direction and location of the needle.
- In a core needle biopsy, a small incision in the skin may be made to clear a path for the needle’s insertion.
- The needle is inserted into the area being tested, and a syringe is used to pull out the cells, tissues or fluid to be tested. In a core needle biopsy, the needle may be attached to a spring-loaded tool that enables it to be inserted and removed quickly.
- A small marker may be left in place where the biopsy was performed, allowing the area that was tested to be easily located in imaging tests if further treatment is needed. This is especially true in biopsies of the breast, where a tiny titanium marker called a biopsy clip is routinely placed at the biopsy site.
- More than one area may need to be tested in order to produce accurate results. If so, a different needle and syringe will be used at each separate site.
- When the site is done being tested it is bandaged over, and the collected sample is sent to the laboratory for analysis.
What are the risks of a needle biopsy?
- Typical side effects from a needle biopsy include pain or soreness, bleeding, bruising and swelling. Normally these will improve over several days as healing takes place.
- If infection or incidental damage to nearby tissue occurs, it should be reported to the doctor.
Results and Follow-Up
What happens in the follow-up after a needle biopsy?
After completion of a needle biopsy and laboratory tests, there are a number of possible outcomes:
- The laboratory may ask for additional samples to be taken in order to make a more accurate reading of results.
- No abnormal cells are found.
- The sample shows a mix of abnormal and normal cells, making it difficult to determine the patient’s level of risk or exact condition. In such cases, additional samples or other types of testing may be called for.
- Precancerous cells are found. If not treated, a cancerous condition could develop.
- Cancer cells are found.
Test results will be explained by the doctor to the patient, and any necessary next steps in treatment will be outlined.