Pseudoangiomatous stromal hyperplasia (PASH) is a rare benign breast lesion in children. We report a 10-year-old girl with hormonally driven gigantomastia and recurrent mastitis, interpreted as a secondary inflammatory complication of rapid breast enlargement. Treatment with oral tamoxifen led to arrest of breast growth and resolution of inflammatory symptoms. This case supports tamoxifen as a potential non-surgical option for hormonally driven pediatric gigantomastia associated with PASH.
