Distinct lymph nodal sonographic characteristics in breast cancer patients at high risk for axillary metastases correlate with the final axillary stage

Abstract

The purpose of this study was to assess the clinical relevance, limitations and most common findings of axillary ultrasound and subsequent image-guided aspiration cytology in clinically node-negative breast cancer patients who are at high risk for axillary metastasis. Following institutional review board approval and Health Insurance Portability and Accountability Act (HIPAA) compliance, sonographic axillary surveys from 112 patients considered at high risk for axillary metastases were reviewed retrospectively for the following abnormal features: asymmetric cortical thickening/lobulations; loss or compression of the hyperechoic medullary region; absence of fatty hilum; abnormal lymph node shape; hypoechoic cortex; admixture of normal and abnormal appearing nodes; and increased peripheral blood flow. Patients with either normal or abnormal ultrasound exams, but negative cytology, underwent sentinel node mapping. Patients with abnormal ultrasound and positive cytology proceeded to complete axillary dissection. The number of positive nodes, the size of tumour deposits and the histological pattern of metastatic disease on the positive nodes were then correlated and compared with their corresponding sonographic abnormalities. Abnormalities related to the lymph node cortex were indicative of N1a disease. Features such as loss or compression of the hyperechoic medullary region, absence of fatty hilum, abnormal lymph node shape and increased peripheral blood flow were predictors of N2–3 disease. In conclusion, nodal sonographic characteristics of patients at high risk for metastases are useful predictors of tumour burden in the axilla. When combined with the results from aspiration cytology, these findings could modify the surgical approach to the axilla, eliminating the need for sentinel node mapping in a significant proportion of patients.