Pleuroparenchymal fibroelastosis in heterogeneous clinical conditions: Clinicopathologic analysis of 7 cases

Background and Aims: Pleuroparenchymal fibroelastosis (PPFE) is classified as a rare idiopathic interstitial pneumonia, and its clinicopathologic features remain unclear. We sought to investigate the clinical, radiologic, and pathologic features of patients with histologically proven PPFE. Methods: Seven patients who had histologic features of PPFE that were definitive or consistent with PPFE were included. Clinical data and radiologic findings of chest computed tomography were obtained. Histologic evaluation was performed by 2 pathologists. Results: Four patients had elevated serum autoantibodies, 3 had a history of organ transplantation, and 1 had acute Aspergillus infection. All patients had various degrees of restrictive patterns on pulmonary function tests. Histologic examination revealed a variable extent of PPFE. Fibroblastic foci, patchy lymphocytic infiltration, and pneumothorax were observed, but these findings were nonspecific. Radiologically, PPFE lesions were distributed diffusely, rather than being limited to the upper lungs. Conclusions: PPFE seems to be a histologic finding that may partly overlap with other chronic lung diseases. There can be various underlying clinical states.