Unilateral upper lung-field pulmonary fibrosis radiologically consistent with pleuroparenchymal fibroelastosis after thoracic surgery: Clinical and radiological courses with autopsy findings

Abstract

Background: Pleuroparenchymal fibroelastosis (PPFE) is a rare idiopathic interstitial pneumonia characterized by pleural and parenchymal involvements predominantly in the upper lobes. Unilateral upper-lung field pulmonary fibrosis (upper-PF) radiologically consistent with PPFE was recently reported in patients with a history of open thoracotomy and presented with impaired thoracic movements in the operated side with unknown mechanisms. This retrospective study aimed to elucidate the clinical and radiological courses and pathological findings of unilateral upper-PF.

Methods: All the consecutive patients diagnosed as having unilateral upper-PF between March 2012 and April 2018 were included. Radiological images and clinical courses before and after the diagnosis were thoroughly reviewed.

Results: Fourteen patients were included. Unilateral upper-PF was diagnosed after a median of 4.8 years from the open thoracotomy or video-assisted thoracic surgery for treating lung or esophageal cancer, or bronchiectasis. Before or at diagnosis, 12 (85.7%) of 14 patients developed aberrant intrathoracic/extrathoracic air suggestive of pleural fistula, although the degree was slight. Of note, the upper-PF lesion apparently deteriorated once aberrant air emerged in all the patients. After diagnosis, the upper-PF lesion transformed into cystic lesion in 9 patients, 4 of whom eventually developed pulmonary aspergillosis. The prognosis was poor, with a median overall survival of 49.3 months. The autopsy in one patient demonstrated findings consistent with PPFE and chronic pleuritis.

Conclusions: Unilateral upper-PF developed after thoracic surgeries and had many clinical, radiological, and pathological characteristics in common with idiopathic PPFE. Our results indicate that the commonly observed aberrant air may be correlated with disease development and progression.

Keywords: Aberrant air; Chronic pleuritis; Pleural fistula; Pleuroparenchymal fibroelastosis; Unilateral.