Pseudoangiomatous stromal hyperplasia: mammographic and sonographic appearances.

Pseudoangiomatous stromal hyperplasia should be included in the differential diagnosis of a circumscribed or partially circumscribed mass, especially in the premenopausal population. These masses often grow over time and can recur locally. Pathologic diagnosis of the lesion may be difficult unless the pathologist is aware of the presence of a mass lesion and appreciates the stromal changes characteristic of such a lesion.