Axillary Metastases on Breast Ultrasound

IMAGING FINDINGS:​
​Abnormal enlarged axillary lymph node with an irregular asymmetrically thickened cortex.
 
 WHY IT MATTERS:

1. Staging of a breast cancer relies heavily on the presence or absence of ipsilateral axillary lymphadenopathy. Identification and sampling of an abnormal lymph node at the time of diagnosis allows for streamlined treatment.
   
   
2. The main signs of metastases within a lymph node include:

                 -   thickened cortex > 3 – 4 mm thick
                 -   focal cortical bulge or eccentric thickening
                 -   irregular margins or encroachment of the fatty hilum
                 -   loss of the normal fatty hilum
For axillary lymph nodes on ultrasound, the overall size (length or width) of the node is not the most important factor. It is the cortical thickness that matters.

FURTHER READING:
US Evaluation of Axillary Lymph Nodes (RadioGraphics, 2014)