Pseudoangiomatous Stromal Hyperplasia on Core Needle Biopsy Does Not Require Surgical Excision

Pseudoangiomatous stromal hyperplasia (PASH) is an uncommon, benign localized fibrotic lesion. Historically, PASH has been difficult to differentiate from angiosarcoma. This difficulty has led to recommendations of surgical excision. We sought to identify the incidence of upgraded pathology to atypia or malignancy on surgical excisional biopsy after identification of PASH on core needle biopsy (CNB). A 5-year retrospective review at a single institution was conducted including all cases of PASH confirmed on CNB. The data set was divided into patients who underwent excisional biopsy and those followed only by imaging. Primary end points included the incidence of subsequent malignancy or high-risk pathology on histologic analysis or the presentation of suspicious imaging. Thirty-seven patients were reviewed, 19 (51.4%) underwent surgical excision and 18 (48.6%) were followed with imaging alone. A palpable mass was noted in 36.8 per cent of patients in the excisional group versus 5.6 per cent in the imaging group (P = 0.02). The median follow-up for the excisional and imaging groups were 43 and 35 months, respectively (P = 0.85). The 95 per cent confidence interval for the presence of malignancy was 0 to 9.4 per cent. Although further characterization of PASH is needed, our data support using CNB with follow-up imaging as a safe alternative to excisional biopsy in the absence of symptoms or other clinical factors. However, further research in this area is needed.