Fine Needle Aspirates: Small Samples, Big Answers

Fine needle aspirates are one of the most useful diagnostic tools available to general practice teams because they’re simple, low-risk and often provide meaningful answers. An FNA uses a tiny needle to collect just a few cells from a mass or organ, and with ultrasound guidance, the sample can be taken precisely from the area most likely to give diagnostic value. It’s quick, minimally invasive and well-tolerated by most patients.

FNAs are often discussed alongside biopsies because both involve sampling, but they serve different clinical purposes. A biopsy collects a larger piece of tissue, providing architectural detail, which makes it essential for certain conditions. However, it also carries a higher risk of bleeding and is best performed in a hospital environment.

SA Vet Sonography performs ultrasound-guided FNAs as part of the mobile service, where they are safe, accurate and appropriate. Biopsies are not performed in the mobile setting; when a biopsy is required, it’s arranged through the referring clinic so it can be done with proper monitoring and support.

For many common presentations, such as lymphoma, mast cell tumours, round cell lesions, and various inflammatory processes, FNAs offer clear diagnostic direction. And when they don’t give a definitive answer, they still provide a safe and valuable first step in the diagnostic decision-making process.Understanding what FNAs can offer is one part of the picture; how we collect them matters just as much.

Ultrasound-guided sampling is not just about steering the needle; it’s about reducing risk and improving accuracy in real time. Visualising the lesion allows precise targeting of the most diagnostic areas, avoiding vessels, reducing trauma and increasing the likelihood of meaningful cytology. This is especially useful for small masses, deep abdominal structures, irregular lesions or anything sitting close to critical anatomy. The guidance matters even more when the patient is uncomfortable, reactive or difficult to palpate, because visualisation maintains safety while keeping the procedure gentle.

When an FNA is likely to help, the process is quick. Most animals tolerate the procedure remarkably well, often requiring no more than gentle handling or mild sedation if they’re anxious or in pain. The risks of bleeding and swelling are low compared to biopsy, and complications are rare. Samples are placed on slides, labelled and submitted through the referring clinic’s usual pathology provider, maintaining continuity of records and case management.

If you’d like to book an FNA or check whether sampling is appropriate for a specific lesion, we’re always happy to assist.