E1054. Beyond the Breast: A Review of Common Extramammary Findings on Breast MRI
  1. Caroline Merriam; Yale New Haven Hospital
  2. John Lewin; Yale New Haven Hospital
Breast MRI is an invaluable and versatile tool in breast imaging. It serves as the modality of choice for breast cancer screening in high-risk patients, evaluating extent of disease, monitoring treatment response to chemoradiation, and determining silicone implant integrity. When compared to ultrasound and mammography, breast MRI encompasses a larger FOV, often including portions of the upper abdomen, lungs, mediastinum, and rib cage. In 2015, a retrospective study conducted by Neill et al. detected incidental extramammary findings in 17% of contrast-enhanced breast MRIs. In a small group of patients, breast MRI incidentally detected previously unknown sites of metastatic disease or primary malignancy outside of the breast. As availability and demand for breast MRI increases, breast imagers will be tasked with recognizing and characterizing a growing number of incidental findings outside of the breast. The goal of this educational exhibit is to provide a systematic review of common incidental extramammary findings on breast MRI. We will focus specifically on findings that significantly impact patient care, prompting adjustments in treatment strategy or recommendations for additional diagnostic imaging.

Educational Goals / Teaching Points
Our goal is to improve diagnosis and expedite management of clinically significant extramammary findings seen on breast MRI. For each incidental extramammary finding, we will review key imaging features, discuss differential diagnoses, and outline recommendations for next steps in management.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
This educational exhibit will discuss several clinically significant extramammary findings identified on breast MRI. These extramammary abnormalities include liver metastases, liver hemangioma, pneumonia, atelectasis, pleural effusion, thyroid nodules, thoracic aortic aneurysm, aberrant right subclavian artery, benign and malignant osseous lesions.

This educational exhibit highlights key imaging features and clinical implications of extramammary findings seen on breast MRI. While benign lesions represent the majority of incidental extramammary findings, breast MRI can reveal abnormalities, such as liver and osseous metastases, which may significantly alter diagnostic work-up and treatment strategy.