Two cases of breast pseudoangiomatous stromal hyperplasia

Abstract

We report two cases of pseudoangiomatous stromal hyperplasia (PASH) of the breast which is a rare entity. Patient 1, a 46-year-old woman was seen at the hospital because of a tumor of the right breast. A 25×25 mm, movable tumor was felt in the upper outer quadrant of the right breast. A possibility of malignancy could not be ruled out from results of ultrasonography and mammography, and aspiration biopsy cytology was class IIIb. Patient 2, a 34-year-old woman, had a 20×15 mm well movable tumor in the lower outer quadrant of the left breast. Results of ultrasonography and aspiration biopsy cytology suggested fibroadenoma which showed a tendency to increase. We excised these tumors under local anesthesia. Pathological examination revealed that the lesions were characterized on histology by the presence of anastomosing slit-like spaces embedded in a thick fibrous stroma. Stromal spindle cells lacked atypia and were immunohistochemically positive for vimentin, alpha-smooth muscle actin, and CD34. Thus the histopathological diagnosis of the lesions was PASH of the breast in both cases.