Fine Needle Aspiration, or FNA, refers to retrieving cells or fluid out of a breast lump or cyst by placing a needle into the target, followed by gentle suction on a syringe. An FNA can be done for either diagnosis (what is that mass?) or treatment (how nice to get rid of a painful cyst!). FNAs accomplish the goal quickly without any scarring.
Cysts, which are benign fluid-filled sacs, can be aspirated easily because they readily collapse under the suction of a syringe. Once aspirated, they usually do not recur.
Solid lumps do not disappear with a fine needle aspiration. The lump can be prominent breast tissue, a benign solid tumor, an atypical mass, or cancer. FNA allows a sample of cells retrieved from the lump to be sent to a pathologist who can give a diagnosis. Sometimes a different biopsy must be done because the FNA does not retrieve enough cells to provide an answer. Other biopsies include core biopsies and excisional biopsies.