Intramammary Node Mimic on Mammography

IMAGING FINDINGS: ​

​Mediolateral oblique (MLO) and craniocaudal (CC) views of the left breast demonstrate two round circumscribed masses in the upper outer quadrant posteriorly. Spot compression view confirms the finding. Ultrasound evaluation demonstrates two adjacent round hypoechoic masses. They do not have the characteristics of a lymph node. Biopsy revealed multifocal invasive ductal carcinoma.

WHY IT MATTERS:

1. Intramammary lymph nodes are a common finding in the upper outer quadrant of the breast. They are a normal variant and do not require further evaluation. However, don’t be fooled. Not all circumscribed masses in the upper outer quadrant are lymph nodes.  
2. Intramammary lymph nodes have a classic appearance with a reniform shape, hyperechoic center on ultrasound, a fatty hilum or notch on mammography and central vascularity.  
   
   

FURTHER READING:
Intramammary Lymph Nodes: Normal and Abnormal Multimodality Imaging Features (BJR 2019)