One hundred and thirty-nine patients with core biopsy (CB)-proven unilateral primary operable invasive breast cancer underwent axillary ultrasound. Lymph nodes were identified on ultrasound in 134 patients (96%), of which 121 (87%) underwent core biopsy. The morphology of all biopsied nodes was noted. Normal lymph node was obtained in 77 CBs, 25 (32%) of which were subsequently shown to have nodal metastases. The results are presented in Table 1. The CB sensitivity for nodes with normal ultrasound morphology was 12%, for those with unilobulated cortex was 64%, for those with multilobulated cortex was 77%, for those with absent hilum was 88% and for those with multilobulated cortex and absent hilum was 100%.

In conclusion, the present study shows that an aggressive CB policy leads to an increase in sensitivity, but of relatively modest proportions, and is at the expense of a large number of normal biopsies. CB is insensitive at detecting micrometastases. CB of nodes with a normal ultrasound morphology is of little utility.