Pseudoangiomatous Hyperplasia of Mammary Stroma: Insights from Two Cases, Data Update and Management Algorithm.

Pseudoangiomatous stromal hyperplasia (PASH) is a benign breast lesion frequently discovered incidentally during imaging or biopsy for other conditions. We present two cases of PASH associated with fibroadenomas in premenopausal women, both presenting as palpable, symptomatic breast masses. In the first case, a 26-year-old woman exhibited a 5.2 cm hypoechoic lesion, initially diagnosed as PASH on core biopsy, later confirmed as fibroadenoma with PASH components post-excision. The second case involved a 37-year-old woman with a painful 5.6 cm mass, diagnosed similarly via biopsy, and later confirmed as fibroadenoma fully colonized by PASH after surgical removal. Both cases highlight the diagnostic challenge in distinguishing PASH from fibroadenomas, given overlapping clinical and imaging features. Hormonal factors, particularly contraceptive use, may contribute to PASH development. Management remains controversial, with surgery indicated for symptomatic lesions, while conservative approaches may suffice for smaller, asymptomatic cases. Based on our findings and current literature, we propose a management algorithm to guide clinicians in differentiating cases warranting surgical intervention from those suitable for monitoring. Further studies are needed to validate this approach.