BACKGROUND Pseudoangiomatous stromal hyperplasia (PASH) is an uncommon benign breast lesion. CASE REPORT PASH is reported in a young female in treatment for neurological diseases with multi-drug therapy (clonazepam, valproate and risperidone). Her menstrual cycles are irregular, and she reached menarche very late. CONCLUSIONS The higher PASH prevalence in premenopausal woman (the majority of whom are actively taking oral contraceptive pills), in 24% to 47% of men with gynecomastia and during pregnancy supports a hormonal etiology; the interaction between clonazepam, valproate, risperidone and progesterone could increase the level of progesterone that could stimulate PASH growth.