Pseudoangiomatous Stromal Hyperplasia

Hormonally stimulated myofibroblastic proliferation.

• Pathology: Anastomosing slit-like spaces lined by myofibroblasts (mimics angiosarcoma histologically but is benign).
• Imaging: Non-specific. Usually looks like a fibroadenoma or developing asymmetry.
• Management: Biopsy required. Excision if growing; otherwise observation.