Fine Needle Aspiration Cytology (FNAC) refers to the puncturing of the abnormal breast lump (either by palpation by the examining doctor or image guided by mammography) with a needle and then aspirating through the hollow needle a sample for analysis under the microscope. If this shows an unequivocal cancer (i.e. cells from the tumour that are unequivocally malignant) then the patient proceeds to staging and appropriate therapy for her stage. If, as often happens, there is a non-diagnostic result from FNAC, then a formal surgical biopsy is performed, and if the abnormal area in the breast is only able to be localised at mammography then the area for biopsy may have to be identified by a guide-wire placed at a mammographic localisation session before the biopsy is attempted.
