What is the management of Pseudoangiomatous stromal hyperplasia (PASH) in premenopausal women?

Management of Pseudoangiomatous Stromal Hyperplasia in Premenopausal Women

Conservative management with observation is the recommended approach for pseudoangiomatous stromal hyperplasia (PASH) in premenopausal women, with surgical excision reserved for lesions that are large (>3 cm), show progressive growth, or have suspicious radiologic features.

Clinical Overview

PASH is a benign mesenchymal proliferative lesion of the breast that predominantly affects premenopausal and perimenopausal women. The condition is hormone-responsive, with approximately 95% of cases showing estrogen or progesterone receptor positivity 1. This hormonal basis explains its prevalence in premenopausal women and rare occurrence in men (typically those with gynecomastia or on hormonal therapy).

Diagnostic Approach

Clinical Presentation

• Most commonly presents as a palpable breast mass (56-96% of cases) 1, 2
• May be discovered incidentally on routine imaging
• No specific or distinguishing features on imaging (mammography, ultrasound, or MRI)

Diagnostic Testing

1. Core needle biopsy (CNB) is the initial diagnostic procedure of choice

   • Diagnostic accuracy of CNB for PASH is approximately 64% 3
   • Negative CNB does not exclude PASH (35% of PASH cases had negative initial CNB) 2

2. Histopathological features

   • Anastomosing slit-shaped spaces lined by spindle cells
   • Positive staining for CD34
   • Negative for factor VIII (distinguishing from angiosarcoma)
   • Positive for hormone receptors (especially progesterone receptors) 4

Management Algorithm

1. For PASH diagnosed on core needle biopsy:

A. Observation is appropriate when:

• Lesion is ≤3 cm
• No suspicious radiologic features
• No rapid growth
• Radiologic-pathologic concordance exists

B. Surgical excision is recommended when:

• Lesion is >3 cm (associated with higher progression rate) 3
• Progressive growth of mass
• Radiologic-pathologic discordance
• Suspicious radiologic features
• Patient preference

2. Follow-up for patients managed with observation:

• Clinical examination and imaging at 6-month intervals initially 2
• If stable for 1-2 years, can transition to routine screening

Prognosis and Recurrence

• Progression rate: 16.6-26% after initial management 3, 2
• Recurrence rate: 13-26% depending on management approach 2
• Factors associated with progression include:
  • Larger lesion size (>3 cm)
  • Enlargement of palpable mass
  • Incomplete excision

Special Considerations

1. Association with other breast pathologies:

   • PASH can coexist with other breast conditions including nonproliferative changes, proliferative changes without atypia, and rarely with malignancy 5
   • Up to 30% of patients may have a diagnosis of cancer or carcinoma in situ at or before the diagnosis of PASH 2

2. Hormonal influence:

   • The strong association with hormone receptors suggests a hormonal basis for PASH development 1
   • Consider the impact of hormonal therapies or pregnancy on PASH lesions

3. Pitfalls to avoid:

   • Do not assume malignancy based on size alone
   • Do not rely solely on core biopsy for large or suspicious lesions
   • Avoid unnecessary extensive surgery for this benign condition

Conclusion

PASH is a benign condition with excellent prognosis. While surgical excision was historically the standard approach, current evidence supports conservative management with observation for most cases in premenopausal women, particularly when lesions are small and stable. Surgical intervention should be reserved for larger lesions, those with progressive growth, or when there is radiologic-pathologic discordance.