Background: In changing our technique to performing needle localization breast biopsies (NLBB) using local anesthesia in an outpatient setting, we investigated whether or not our complication rates with local anesthesia were acceptable when compared with complications from a cohort of biopsies of the breast performed for palpable masses. We were also interested in determining whether or not our rate of missed biopsies was within acceptable ranges.
Study design: Complications occurring in 283 patients who underwent 301 NLBB using local anesthesia between 1983 and 1991 were compared with complications occurring after excision of 249 palpable masses of the breast excised using local anesthesia during this period.
Results: Complications associated with NLBB were missed lesions, six (1.99 percent) of 301; hematoma, 12 (3.99 percent) of 301; abscess, three (0.99 percent) of 301; seroma, one (0.33 percent) of 301, and wound separation, two (0.66 percent) of 301, for a total of 24 complications (7.96 percent). These rates were not statistically different from the rates of complication after biopsies of palpable lesions using local anesthesia (p < 0.49). The 301 NLBB revealed 87 carcinomas (28.9 percent); 50 invasive and 37 in situ. Of the nonpalpable carcinomas, 43 percent were in situ. Only 11 percent carcinomas, 43 percent were in situ. Only 11 percent of the palpable lesions were in situ (p < 0.001). Forty-four patients with nonpalpable invasive carcinoma had a 25 percent rate of positive axillary lymph nodes.
Conclusions: Needle localization breast biopsies can be performed using local anesthesia exclusively with less than a 2 percent chance of missed lesions and complication rates similar to those associated with biopsies of palpable lesions. The biology of these lesions varies. Although there is a high rate of in situ carcinoma, there is a significant rate of node positivity in the patients with nonpalpable invasive carcinoma.