The effect of needle gauge and local anaesthetic on the diagnostic accuracy of breast fine-needle aspiration cytology

Aims:The value of breast fine needle aspiration cytology (FNAC) is well established. This prospective study evaluates the effects of local anaesthetic (LA) and different gauge needles on the diagnostic accuracy of breast FNAC.Methods:Aspirates were obtained from 59 consecutive excised breast tumours (51 malignant, eight benign) using green (21-G) and blue-hub (23-G) needles, both before and after infiltration of LA at the aspiration site.Results:There was good agreement for the cytological diagnosis of each tumour when compared by needle size (κ=0.85) and the presence of LA (κ=0.77). Diagnostic sensitivity ranged from 88 to 92%. None of the differences were statistically significant. In addition LA appeared to have no effect upon the cytological grading of breast carcinomas (2=1.98,df3,P=0.58).Discussion:The use of the smaller gauge blue-hub needle or LA does not appear to affect adversely the diagnostic accuracy of breast FNAC. Whether using LA or the blue needle routinely in the breast clinic will have an effect upon the discomfort experienced during FNAC remains to be proven.