Fine needle aspiration cytology is a procedure that uses a small, hollow needle to gently puncture the skin into a lesion to obtain a small sample of cells or fluid from a tumor or an organ under the skin for testing, to determine whether the lesion is benign or malignant.

Fine needle aspiration (FNA) is a widely used method for breast cytology diagnosis in the world. FNA is useful because it is a simple, quick, inexpensive, and less complicated diagnostic technique with high accuracy (sensitivity 80-100%, specificity over 99%).

Fine needle aspiration (FNA) cytology is a minimally invasive, rapid, and inexpensive technique. The accuracy of FNA in diagnosing benign and malignant lymph node diseases is over 90%; however, the sensitivity of this method varies greatly between benign and malignant, primary and secondary disease groups.

If exfoliative cytology is based on natural or artificially exfoliated cells to diagnose diseases, aspiration cytology is based on cells aspirated from tissues and organs with a small needle (with a diameter of ≤ 22G).