Tumoral Pseudoangiomatous Stromal Hyperplasia of the Breast

Tumoral pseudoangiomatous stromal hyperplasia (PASH) is a rare benign proliferative disease of the breast. The majority of the literature reports of PASH have not contained detailed descriptions of the imaging characteristics of PASH. A 10-year retrospective study of patients with tumoral PASH and a 20-year Ovid MEDLINE search were performed to determine whether specific imaging and needle biopsy results could characterize PASH preoperatively. We identified 22 patients with tumoral PASH. Seventeen (77%) of 22 women had a palpable lump and 14 (72%) of 21 had a density on mammography. Ultrasound (US) findings included mixed or hypoechoic echogenicity in 83 per cent and ill-defined borders in 62 per cent. Eight (36%) patients had lesions with a Breast Imaging Reporting and Data System (BI-RADS) classification of 4 or 5. The sensitivity of preoperative core needle biopsy (CNB) to identify PASH was 83 per cent. A review of the literature revealed that 90 per cent of patients with PASH had some malignant imaging characteristics and 95 per cent had a mass on mammography. The imaging characteristics of PASH exhibited marked variability. Excision of PASH after CNB may be considered for patients with symptoms, enlarging lesions, or lesions classified as BI-RADS 4 or 5. PASH diagnosed by CNB allows selected patients to avoid excision.