What should you know about fine needle aspiration technique?

A clinician cleans the skin and guides a fine needle into the area being assessed. The needle may be moved gently within a lump to gather enough cells, or used to draw out fluid. A syringe is usually attached to the needle. The material goes to a laboratory, where it is assessed under a microscope and may undergo additional testing.

FNA can help assess a thyroid nodule, lymph node, breast lump, or another accessible abnormal area. It does not remove the whole lump. Ultrasound or another imaging method may help guide the needle when the target is deep or small.

Tell the clinic about medicines that affect bleeding, allergies, pregnancy, and any difficulty staying still. Follow the instructions you receive about eating, drinking, or pausing a medicine; do not stop prescribed treatment without guidance.

During sampling, you may feel pressure, a brief sting, or pulling. Afterward, keep the area clean and follow the dressing instructions. Mild tenderness or bruising can occur. Ask when the result is expected and how it will be explained, because the report may need to be interpreted alongside examination and imaging.

Contact the clinic if bleeding continues despite firm pressure, swelling keeps increasing, pain becomes difficult to control, or the site becomes increasingly red, warm, or produces discharge. Seek urgent help for trouble breathing, fainting, or sudden severe swelling, especially after a neck procedure.

What area will you sample, and will imaging guide the needle? What should I do with my regular medicines? When should I expect the report, and could the sample be insufficient or need another test?