Do All Women with Abnormal Sonographic Axillary Lymph Nodes Need a Biopsy?

Purpose: With the increased use of breast ultrasound for different indications, sonographically abnormal axillary lymph nodes are not a rare finding. We examined clinical and imaging characteristics in correlation with pathological reports of the sonographic guided biopsies to assess the yield of needle biopsy of these nodes. Methods: Clinical, imaging and pathology data were collected for 171 consecutive patients who underwent sonographic guided needle biopsy of an abnormal lymph node between 2008 and 2013. Malignancy rates were examined for different clinical settings: palpable axillary mass, previous history of breast cancer, findings suggestive of a systemic disease, and those with a breast finding of low suspicion or an incidental abnormal axillary lymph node. Patients with newly diagnosed breast cancer were excluded. Results: Twelve patients (7%) were found to have a malignancy on their axillary lymph node biopsy. Malignancy rates increased with age, and varied with clinical presentation: Axillary mass (8, 26%); history of breast cancer (2, 11%); systemic disease (0%) and breast finding of low suspicion or incidental abnormal lymph node on screening (1, 1%). Low rates of malignancy were found when the cortex was <6 mm (1, 0.8%). The most important imaging finding associated with malignancy was lack of a preserved hilum, in which case almost a third (10, 29%) of the biopsies were malignant. Only 1 of 89 women with a breast finding of low suspicion or an incidental abnormal axillary lymph node was found to have malignancy. In this case the lymph node had no hilum. Conclusions: In women without breast cancer, a highly suspicious breast mass or an axillary mass, more stringent criteria should be used when evaluating an abnormal axillary lymph node on sonography, as the malignancy rates are very low (1%).