Harris CK, et al. - This research explored the role of positive ultrasound (US)-guided lymph node needle biopsy in breast cancer in axillary lymph node (LN) dissection. N1 disease was reported in more than half of patients without palpable adenopathy but with preoperative US-guided biopsy proven axillary LN metastases. For patients presenting with both tumor size ≤2 cm and only 1 abnormal LN on axillary ultrasound (axUS), 73% appeared to have N1 disease. Such patients could attempt at sentinel LN biopsy (SLNB) if they were otherwise analogous to Z11 patients.