From the Guidelines
Pseudoangiomatous stromal hyperplasia (PASH) of the breast is a benign condition that typically does not require treatment, and for asymptomatic, small lesions with confirmed diagnosis through core needle biopsy, clinical observation with regular follow-up is recommended. The diagnosis of PASH is often made incidentally during breast imaging or biopsy for other concerns. According to the guidelines for evaluating a dominant mass in women aged 30 years or older, the initial evaluation begins with a bilateral diagnostic mammogram, followed by an ultrasound for BI-RADS categories 1,2, and 3, and tissue diagnosis through core needle biopsy (CNB) or needle localization excisional biopsy for BI-RADS categories 4 and 5 1.
For PASH, the standard approach to management is watchful waiting, with regular follow-up to assess stability, as the condition is benign and has no known association with increased breast cancer risk. However, if the lesion is large, growing, or causing symptoms such as pain or cosmetic concerns, surgical excision may be considered, with a wide local excision with clear margins to prevent recurrence. Hormonal therapy, such as tamoxifen, has been used in some cases, particularly for diffuse or recurrent PASH, though evidence for its effectiveness is limited 1.
Key points to consider in the management of PASH include:
- Clinical observation with regular follow-up for asymptomatic, small lesions
- Surgical excision for large, growing, or symptomatic lesions
- Wide local excision with clear margins to prevent recurrence
- Limited role for hormonal therapy, such as tamoxifen
- No known association with increased breast cancer risk, so management focuses on symptom relief and ruling out malignancy rather than cancer prevention.
From the Research
Diagnosis of Pseudoangiomatous Stromal Hyperplasia (PASH)
- PASH is a benign, proliferative lesion of the breast that can be diagnosed through core needle biopsy (CNB) or surgical excision 2, 3, 4.
- Imaging findings of PASH are nonspecific, making it difficult to diagnose through radiological imaging alone 2, 3, 4.
- CNB is sufficient to confirm PASH, but surgical excision may be necessary to rule out occult malignancy or to manage large lesions 2, 3, 4.
Treatment of Pseudoangiomatous Stromal Hyperplasia (PASH)
- Treatment options for PASH include medical treatment with hormonal management for asymptomatic patients, local excision, and breast reduction in rare cases 5.
- Surgical excision is generally not necessary, but may be required to manage large lesions (>3 cm) or progressive growth of a PASH lesion 3, 4.
- Close monitoring or surgical excision are required to manage large lesions or progressive growth of a PASH lesion 2, 3.
- In rare cases, mastectomy may be necessary to manage bilateral, diffuse, recurrent PASH 6, 5.
- Immediate implantation after mastectomy may be a suitable option for carefully selected patients with large, relapsing bilateral benign breast diseases, but the decision should be made on a case-by-case basis 5.
Management of PASH
- A diagnosis of PASH on core biopsy in the absence of suspicious radiologic features may be managed with follow-up and imaging at a 6-month interval 2.
- Growth, suspicious radiologic findings, or inconclusive biopsy warrants surgical excision 2, 3, 4.
- Close surveillance is necessary given the recurrence rate of 13-26% 2, 3.