Abstract
It is generally accepted that ultrasound (US) is a useful examination to detect normal and abnormal lymph nodes in patients with breast cancer. Although normal or reactive level I lymph nodes can be detected by US, no consensus has been reached about the usefulness of US to detect Level II lymph nodes. The purpose of this study was to evaluate the frequency of detection and nature of level II lymph nodes detected by US in healthy women and also to assess if the tool can be used for the diagnosis and treatment of breast cancer. A total of 5228 women underwent breast US as part of opportunistic breast cancer screening at our center from March to August 2018. The images included those of 5036 healthy women, excluding those who had a current or previous history of axillary lymph node metastasis. Routine screening US breast images were evaluated with regard to the frequency of detection of the lymph nodes and the characteristics of the detected lymph nodes. Level II lymph nodes were detected in 348 women (6.9%) and 490 lymph nodes were detected either unilaterally or bilaterally. The L/T ratio of the lymph nodes was less than 2.0 in 144 (29.4%) and greater than 2.2 in 346 (70.6%) nodes. Thus, approximately one-third of the subjects had lymph nodes with a round configuration.
In conclusion, it should be kept in mind that normal or reactive lymph nodes can be detected by US in about 7% of healthy women.
