Pseudoangiomatous stromal hyperplasia of the breast: a contemporary approach to its clinical and radiologic features and ideal management.

BACKGROUND: Pseudoangiomatous stromal hyperplasia (PASH) is a benign, proliferative lesion of the breast whose clinical relevance, presentation, and optimal treatment remains described incompletely. The purpose of this study is to review the clinical, radiologic, and histopathologic features and appropriate management.

METHODS: Patients diagnosed with PASH were identified from our pathology database between 2000 and 2009. Clinicopathologic data including presentation, diagnosis, imaging, and histology were reviewed. All specimens were confirmed by a single pathologist.

RESULTS: We identified PASH in 80 patients. Median follow-up was 3.71 years (range, 0.45-9.42). Age ranged from 12 to 65 (median, 45) and 95% were female. Lesions were palpable in 56% and found on imaging in the remainder. Core biopsy was performed in 65 of 80 patients (81%), which confirmed a diagnosis of PASH in 65%. The other 23 of 65 patients (35%) required operative excision for diagnosis. There was a progression rate of 26% in the observation arm versus 13% in the excision arm. A diagnosis of cancer or carcinoma in situ was seen in 30% at or before the diagnosis of PASH.

CONCLUSION: PASH may present as a mass, radiologic lesion, or incidentally in pathology specimens. It may be associated with cancerous or precancerous lesions. A diagnosis on core biopsy in the absence of suspicious radiologic features may be managed with follow-up and imaging at a 6-month interval. In this series, 35% of patients with PASH had a negative core biopsy. Growth, suspicious radiologic findings, or inconclusive biopsy warrants surgical excision. Close surveillance is necessary given its recurrence rate of 13-26%.