Evaluation of needle size for breast biopsy: comparison of 14-, 16-, and 18-gauge biopsy needles.

Abstract

The purpose of our study was to compare the quantity and quality of tissue harvested from breast biopsy when using 14-, 16-, and 18-gauge "long-throw" needles. We performed a prospective randomized study in 64 patients with 66 breast lesions. Under stereotactic guidance, passes were made in random order with each of the three biopsy needles in each lesion. Samples were measured for tissue area and scored for their quality. All lesions, including benign and malignant lesions and lesions with and without microcalcifications, were analyzed. Findings of the biopsy samples were compared with the final diagnoses made at surgical excision. In all 66 lesions, 14-gauge biopsy needles obtained significantly larger specimens (14-gauge, 13.14 mm2; 16-gauge, 9.6 mm2; 18-gauge, 6.41 mm2; p < .05) and scored significantly better (14-gauge, 8.37; 16-gauge, 7.56; 18-gauge, 7.14; p < .016) than either of the smaller needles. The results for malignant and benign lesions and for lesions with and without microcalcifications were similar but not equal to the overall results. However, benign lesions and areas with microcalcifications seem to be more problematic for both smaller needles than for 14-gauge needles. Our results indicate that the quantity and quality of breast biopsy specimens depend on the needle size. Of the three needle sizes tested, only 14-gauge long-throw biopsy needles can be recommended for breast biopsy.