Pseudoangiomatous stromal hyperplasia causing massive unilateral breast enlargement-a case report.

Background: Pseudoangiomatous stromal hyperplasia (PASH) is an uncommon mesenchymal benign breast neoplasm. PASH may present as a rapidly growing mass in pre-menopausal women. It is important to rule out other causes of a breast lump including fibroadenoma, hamartoma, phyllodes tumour and invasive adenocarcinoma.