The Faces of PASH -- You May Be Surprised

Background: Pseudoangiomatous stromal hyperplasia is a benign proliferative lesion of the breast, which is more commonly referred to by its acronym PASH. It is of mesenchymal origin and is an uncommon breast lesion traditionally associated with premenopausal women. Histologically, it is defined by proliferation of stromal myofibroblasts and slit-like spaces lined by spindle cells in a collagenous stroma. Objective: To provide a single institution's experience with PASH. Design/Methods: A pathologic database was searched to identify all cases diagnosed as PASH through surgical excision or image-guided biopsy over a 6-year retrospective period. Medical records were reviewed and information was gathered, including patient demographics, personal or family history of breast cancer, clinical and imaging presentation, and subsequent treatment. All imaging studies were reviewed when available. A single pathologist involved in the study also reviewed the hematoxylin and eosin-stained sections more...