Pleuroparenchymal fibroelastosis presenting with pneumothorax.

A 47-year-old woman presented with spontaneous right side pneumothorax. Image studies showed consolidations and reticular opacities involving the pleural and subpleural regions of bilateral lungs. Wedge biopsy specimens of right upper, middle and lower lobes showed fibrosis of the visceral pleura and subpleural area in all three lobes, more significant in the upper lobe. Elastic Van Gieson stain showed a pattern of alveolar septal elastosis with intra-alveolar fibrosis. The clinical presentation and pathological findings are compatible with pleuroparenchymal fibroelastosis, a rare and distinct type of interstitial lung disease. This entity is different from usual interstitial pneumonia by its relationship to pleura, upper lobe predominance and temporal homogeneity. It is different from non-specific interstitial pneumonia by its pleural involvement and scanty inflammatory cell infiltration. Pleuroparenchymal fibroelastosis is a slowly progressive disease; about half of the patients die in 10 years. No curative treatment is available at present time.