When there is doubt about the significance of a lump in a group of lymph nodes or an area is identified by some form of radiological imaging, a fine gauge needle can be used to obtain a small amount of tissue for testing (microscopy). It is often the easiest method for obtaining a pathological diagnosis.

Fine needle biopsies are quite common, very simple and usually only take a few minutes. When the area to be investigated is not easy to locate, imaging techniques such as ultrasound and CT scanning are used to guide the biopsy needle.

What happens in a FNAB?

	If palpable, the pathologist identifies the lump and gently stabilizes it between his fingers.
	After cleansing the skin, a fine needle is passed through the skin and into the lump. Cells from the mass are collected in the hollow bore of the needle. This process typically involves little or no discomfort and takes only a moment.
	The material (cells) collected in the needle are then spread on a glass microscope slide and examined under a microscope.
	In addition to standard cytology stains, special examinations with specific antibody based stains can also be used to increase the accuracy of diagnosis.

Frequently Asked Questions

What can be biopsied with this procedure?

Almost all lumps are suitable for Fine Needle Aspiration (FNA). Lymph glands and skin lumps are the most common sites that are biopsied.  Deeper lesions may be biopsied using radiological guidance in the Department of Radiology.

What are the advantages over an invasive procedure?

FNA biopsy is easily done in an outpatient setting, as a relatively quick and safe procedure, with a reasonably high degree of diagnostic accuracy.  Since not all lumps/bumps are due to cancer, FNA is particularly useful in the initial assessment, and helping the clinician to plan further management/treatment.

What does the procedure involve?

FNA involves the use of a very thin needle (smaller than a blood-collecting needle).  After cleaning the area to be biopsied, the needle is placed inside the lump for 10-15 seconds to obtain material, and then withdrawn.  Part of the material is then stained and examined under a microscope, and the amount of sample required for diagnosis is determined.  Generally, several needlings may be required in order to either sample different parts of the mass or to ensure an adequate sample.  The biopsied area is then covered with a band-aid (if necessary).  The specimen is further examined after the procedure, involving further stains and microscopic examination.

Are there any further risks associated with this procedure?

The risks of FNA are very minimal.  They include a bruise with resultant tenderness, particularly in vascular areas (eg thyroid).  Local pressure is applied to the biopsy area to minimise this problem.  Rarely, infection may occur.

How long does it take to get the results from a biopsy?

One of the advantages of FNA is that a preliminary diagnosis can generally be obtained within 15-30 minutes after the procedure, however, as the remaining material still requires processing, the final diagnosis will be sent to your referring doctor within 2 to 3 days.

Is anaesthetic used?  

In most instances, superficial lumps require no anaesthesia.

What is a large core needle biopsy, and are they effective?

Large-core needle biopsies are a different way of biopsying masses.  The large-core needle biopsies are significantly bigger than the FNA needles, and are an effective way of biopsying larger masses.  A local anaesthetic is used during this procedure, and the small 3-4mm skin incision is closed with either steristrips or a suture.  Being larger than an FNA, the core needles have a greater risk of local bleeding and bruising.

How long does the procedure take?

20 to 30 minutes.