E4906. Pseudoangiomatous Stromal Hyperplasia: Case-Focused Multimodality Imaging and Pathology Review
  1. Brianna Chu; Geisinger Medical Center
  2. Beatriz Olivera; Geisinger Medical Center
  3. Monica Froicu; Geisinger Medical Center
Pseudoangiomatous stromal hyperplasia (PASH) is a benign entity with a variety of radiological presentations. These include characteristically benign masses to mimics of breast malignancy, which have overlapping clinical and morphological features. Clinical presentations vary, such as breast enlargement or a palpable mass, or it may be incidentally found in biopsy specimens. PASH is evidenced histologically by dense stromal fibrosis with slit-like spaces that surround normal breast lobules. Correlation with radiological appearance is vital in establishing an accurate diagnosis and recommending the appropriate management.

Educational Goals / Teaching Points
In this exhibit, we will highlight the clinical presentation, imaging, and radiologic-pathologic correlation of a variety of presentations of PASH. These cases are presented to distinguish imaging features that can guide the management steps such as observation, biopsy, or surgical consultation.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
This pictorial review will illustrate a range of mammographic (circumscribed mass, architectural distortion, asymmetry, calcifications), sonographic (solid or mixed solid and cystic mass) and MRI (mass, nonmass enhancement) features of PASH. Each individual case will show the clinical, mammographic, sonographic, and additional imaging related to the case and the histopathological characteristics. The radiologic-pathologic correlation and management of lesions will also be discussed.

PASH is a radiologically diverse entity that requires multimodality evaluation. The breast radiologist must be familiar with common and uncommon presentations of PASH and consider the clinical and histological findings to improve radiology-pathology concordance. Recognition of imaging characteristics of PASH in the appropriate clinical context can decrease the discordant rate and improve patient management.