Pseudoangiomatous stromal hyperplasia: a study of the mammographic and sonographic features

Aim: To review the imaging features on mammogram and ultrasound of pseudoangiomatous stromal hyperplasia (PASH) of the breast. Materials and methods: A systematic search of the breast cancer screening centre and pathology department database at a teaching hospital was performed to identify cases reported as PASH between 2000 and 2007. The findings on mammogram and ultrasound were reviewed. Information on demographics and clinical outcome were obtained from the patient's medical records. Results: Seventy-three cases of PASH were identified, which occurred in women with a mean age of 51.1 ± 10.5 years. The mean size of the lesion was 18 mm. Up to 70.8% of cases were radiologically detected and 29.2% presented as palpable masses. The most common appearance on mammography was of a solitary, non-calcified mass (30.4%) or localized increased stroma (30.4%). The distribution of mammographic findings differed in screen-detected patients compared with those presenting clinically (p = 0.015, Fisher's exact test). The most frequent sonographic appearance was of a well-defined hypoechoic mass (36.7%). Conclusion: Although there are emerging patterns associated with PASH on imaging, the features are not sufficiently specific to allow for a prospective diagnosis. Histological confirmation, preferably with core biopsy, should always be considered.