The fine needle aspiration (or, but of a different extent of removal, the needle biopsy) is a procedure that is based on the collection of biological material (sample of liquid or tissue from muscles, bones and other organs), performed, precisely, using a needle . The sample taken is then subjected to analysis by the laboratory that performs the cytological or histological examination. In fact it is in effect a biopsy but less invasive. The "objective of the examination" is to establish with certainty the presence of a disease, ascertain its nature, follow its progress, plan a correct therapeutic process and evaluate the effectiveness of the treatment.
As mentioned initially, there are two methods available for tissue sampling: fine needle aspiration and needle biopsy.
The main difference between the two procedures is the type of needle used and the material taken.
The fine needle aspiration uses very fine needles to collect cells and fluids (thyroid follicles, mammary epithelial cells, bone marrow stem cells).
Needle biopsy uses needles with a larger caliber for the removal of small tissue fragments (lung, breast, prostate tissue).
It is used to detect:
- a mass or lump (cyst, infection, benign or malignant tumor)
- an inflammation (it causes)
- an infection (responsible pathogen)
The examination is minimally invasive and involves the collection of a sample of cells, tissue or liquid to be subjected to cytological / histological examination.The collection can be followed under ultrasound guidance, X-ray scan, CT scan or nuclear magnetic resonance (NMR). A needle is introduced into the tissue area to be examined until the suspicious formation is reached, from which part of the content is then collected to be subjected to laboratory analysis.
The exam is performed at specialized and equipped facilities. It can be performed without anesthesia or under local anesthesia, depending on the type of needle used and the procedure adopted.
The patient is made to lie down on a bed, the skin area is disinfected at the point to be analyzed, an anesthesia is applied if necessary, and then the needle is inserted to reach the target area. Aspiration of the sample can take place via a normal syringe or a large hollow needle. The procedure can last from a few minutes to a quarter of an hour. At the end of the examination, depending on the sample taken, the patient can go home or remain under observation for a few hours.
The collected material is sent to the laboratory where it will be examined by the pathologist (doctor specializing in the study of cell and tissue samples).
When should the exam be performed?
The examination must be performed when suspicious microcalcifications, nodules or visible lesions emerge from ultrasound examinations, nuclear magnetic resonance imaging.
Preparation for the exam
The exam does not require special preparation. However, it is advisable to suspend blood-thinning drugs (aspirin, ibuprofen, motrin) a few days before sampling, to minimize the possibility of bleeding after or during the examination. You should consult with your primary care physician to assess the need for alternative therapy. Depending on the area of the body that needs to be analyzed, your doctor may ask you not to eat and drink before the procedure.
Complications following the examination
Generally there are no complications, only in very rare cases could the following occur:
- slight bleeding
- fainting (mainly due to a very anxious emotional state)
The results of the examination (report) may be available within two weeks.
The report usually presents:
- a brief description of the sample in general
- a description of the cells or tissue as they appear under a microscope
- the pathologist's diagnosis
The results will allow a complete evaluation of the cellular and tissue characteristics, allowing a certain diagnosis and a prognostic orientation essential for a correct therapeutic program.
Mayo Clinic. Needle biopsy (English)
NHS. Biopsy (English)