Objective:

To report the pathological features observed in a pulmonary artery biopsy from a patient with pulmonary arterial hypertension (PAH) associated with a BMPR2 variant.

Approach:

• Patient Presentation: A 47-year-old male with a history of dyspnea and recurrent hemoptysis underwent right heart catheterization confirming PAH.
• Biopsy Procedure: A pulmonary artery biopsy was performed to exclude alternative diagnoses such as vasculitis and chronic thromboembolism.
• Histological Analysis: Histological examination revealed foam cell accumulation, inflammatory cell infiltration, and mucoid deposition.

Key Findings:

• The patient had a BMPR2 variant (c.246A > G) linked to PAH.
• Histology showed foam cell accumulation in the intima, infiltration of CD3+ T cells, CD20+ B cells, and CD68+ histiocytes in the intima and media, and mucoid deposition.
• Targeted PAH therapy improved symptoms and resolved hemoptysis after bronchial artery embolization.

Interpretation:

The biopsy provided pathological insights into BMPR2-associated PAH, highlighting inflammation and lipid metabolism dysregulation.

Limitations:

• The variant's significance is uncertain.
• Family genetic analysis was not performed due to the patient's parents being deceased.
• The biopsy did not change the overall management of PAH.

Conclusion:

The findings suggest a link between BMPR2 mutations, inflammation, and lipid metabolism in PAH.