[Percutaneous biopsy in the definition of breast lesions: fine needle vs. 14-gauge]

Any breast lesion/abnormality detected at mammography must be characterized as (non)-neoplastic before surgery. Fine needle aspiration cytology (FNAC) permits a precise diagnosis in over 70% of cases but exhibits many inadequate, false negatives or questionable findings. This makes surgical biopsy mandatory in many cases. An alternative is offered by fine needle biopsy (FNB: 16-18 G needles) or by large core biopsy (LCB: 14 G needles), which procedures can reduce the number of questionable diagnoses with no major discomfort or side-effects for the patient.

January, 1996, to October, 1997, we performed 422 microhistologic biopsies on breast lesions at the Unità Integrata di Senologia, Azienda Ospedaliera Careggi, Florence, Italy. 383 of these lesions were nonpalpable. FNB was performed in 221 cases and LCB in 201. Most biopsies (65%) were carried out under US guidance and some others (25%) under stereotactic guidance.

Microhistologic biopsy allowed accurate lesion characterization in most cases, even though LCB obviously performed much better. Samples were inadequate in 5.88% of cases with FNB and only in 2.98% of cases with LCB. The false negative rate was 1.92% for FNB and 0.99% for LCB. Surgical biopsy was needed for an unquestionable diagnosis only in 9.5% of FNB and 3.9% of LCB cases.

Our results confirm the literature data on how LCB can be considered a valid alternative to surgical biopsy (and, to some extent, to FNAC); in particular, its advantages are: moderate invasiveness, little patient discomfort and high diagnostic accuracy. Moreover, the procedure is short (5-10 minutes) and costs much less than surgical biopsies (1/2 to 1/4).