Ultrasonographic detection of metastatic axillary lymph nodes in breast cancer.

Metastatic involvement of the axillary lymph nodes is the most important prognostic factor in breast cancer. Preoperative knowledge of lymph node status would be useful in planning the therapy for breast cancer. The aim of our study was to find how accurately metastatic lymph nodes can be detected with ultrasonography (US). Our study consisted of 63 breast cancer patients having 65 breast cancers. Their axillae were examined preoperatively with US (with a 7.5 Mhz linear-array transducer). 27.7% of these patients had metastatic axillary lymph nodes. With US we could detect 12 of these 18 axillary metastases. In 2 of our 6 false negative results only micrometastases were found on histological examination. In our study the sensitivity of US was 66.6%. There was only one axilla, in which nodes were detected with US, but on histological examination no metastases were found, thus giving a specificity of 97.9%. Our study indicates that in the axilla normal nodes are not visible with US.