ABSTRACT
PURPOSE: Pseudoangiomatous stromal hyperplasia (PASH) of the breast is a rare, benign condition that can be mistaken as a fibroadenoma on an ultrasound examination or as a low-grade angiosarcoma on a histological examination. The objective of this study was to evaluate the ultrasound features and to present biopsy methods to correctly identify PASH. PATIENTS AND METHODS: We retrospectively reviewed the data of 55 women who were diagnosed with PASH of the breast. Ultrasound features were evaluated according to the Breast Imaging Reporting and Data System (BI-RADS; American College of Radiology). The diagnostic ability of different biopsy methods such as core needle biopsy, vacuum-assisted biopsy and excisional biopsy were analyzed with the final histopathological results of surgical specimens. RESULTS: PASH presented as a circumscribed solid mass, with hypoechoic texture with or without heterogeneity, and a parallel orientation. The features of small, internal cysts or vascular channels and no calcifications can be used to differentiate the lesions from fibroadenomas. A core needle biopsy misdiagnosed PASH in 13 cases out of 28 cases and vacuum-assisted biopsy correctly identified PASH in all 3 cases. CONCLUSION: Ultrasound features of PASH should be noted when performing a biopsy. For inconclusive cases of PASH, an excisional biopsy followed by an initial core biopsy should be performed.