Pseudoangiomatous stromal hyperplasia of the breast: multimodality imaging findings

Abstract

Background/Aim: Pseudoangiomatous stromal hyperplasia (PASH) is a rare benign mesenchymal proliferative breast lesion. The literature contains little information on the radiological results of this uncommon tumor. In this study, we aim to define the radiologic findings of PASH through our institutional experience.
 Materials and Methods: Patients with PASH of the breast reported in the surgical database of our institution from 2020 to 2023 were retrospectively reviewed. PASH was detected in 11 female patients among the patients who underwent a total of 2172 breast tru-cut biopsies. Nine patients whose imaging studies could be recalled from the picture archiving systems (PACS) were included in the study. BI-RADS, 5th edition, was used to analyze and classify radiologic findings.
 Results: The median age of cases was 41 (range 22–53). Our single-center incidence was found to be 0.5%. Considering the sonographic findings, all of the lesions had an oval shape. On mammography, they were defined as focal asymmetry or circumscribed masses. An MRI was available in three cases. All three cases were hypointense on T1-weighted sequences and hyperintense on T2-weighted sequences. They displayed type 1 or type 2 enhancement curves in the dynamic contrast-enhanced images. No diffusion restriction was detected.
 Conclusion: In this study, tumor-forming PASH were generally circumscribed oval hypoechoic solid masses with minimal vascularity and no posterior acoustic features on ultrasound. On mammography, calcification, architectural distortion, or spiculation were not present in any of the cases. MRI findings were t2 hyperintensity, type 1–2 enhancement kinetics, and no diffusion restriction. In all imaging modalities, the imaging characteristics point to a benign lesion.