What is the definition or description of: fine needle aspiration?

Checking the cells: Fine needle aspiration or fna in brief is a procedure that the health care provider inserts a small needle in the tissue of concern in your body and withdraws some cells (or fluid). Usually they send these cells on slides and/or in a special preservative to the lab for cytology diagnosis. If the aspiration was from a cyst and the fluid appeared benign to the provider it may be discarded.