E2617. Complex Solid and Cystic Masses of the Breast: A Radiologic Review
  1. Catherine McNulty; UCLA
  2. Daniel Bradley; UCLA
A complex solid and cystic mass, as the name suggests, contains both solid and cystic components. In the breast, complex solid and cystic masses require careful evaluation because they have a considerable possibility of representing malignancy. Unfortunately, malignant complex solid and cystic masses may have significant imaging overlap with benign masses, making clinical management of these findings difficult. This exhibit will review the imaging features of various complex solid and cystic breast masses and highlight key characteristics to help differentiate them in clinical practice.

Educational Goals / Teaching Points
This exhibit will first briefly describe the differences between a simple cyst, complicated cyst, and complex solid and cystic mass. Subsequently, we will discuss the sonographic, mammographic, and (if applicable) MRI features of various complex solid and cystic masses through a series of cases. The case series will include benign processes (e.g., abscesses, hematomas, fat necrosis, galactoceles), high-risk lesions (e.g., atypical papilloma, phyllodes tumors), and malignancies. With each case, there will be a specific focus on key diagnostic features to help differentiate these masses from one another, using the BI-RADS framework to aid in lesion characterization/management. Epidemiology and potential treatments will also be reviewed.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
This exhibit will focus on mammographic, sonographic, and MRI findings that can be used to highlight the key features of each mass. Specific imaging findings discussed will include mammographic density, shape, margins, echo patterns, posterior sonographic features, calcifications, vascularity, MRI signal characteristics, and degree of enhancement on MRI. Secondary imaging features such as skin thickening, adenopathy, and edema/trabecular thickening will also be examined.

Given the risk of malignancy with complex solid and cystic masses - and the significant overlapping features between benign, high-risk, and malignant processes – the ability to recognize features differentiating benign masses from those requiring further workup is essential.