Case Report: Idiopathic pleuroparenchymal fibroelastosis.

Idiopathic pleuroparenchymal fibroelastosis (IPPFE) is a very rare and a slowly conspicuous progressing chronic lung disease, which usually involves the upper lobes of the lung. This unusual disease, first recognized as a rare idiopathic interstitial pneumonia in 2013, is characterized by dense fibrosis of the visceral pleura and the subjacent lung parenchyma accompanied by elastosis predominating in the subpleural alveolar walls. In the interest of improving our understanding of this uncommon disease, we report a case of IPPFE established by pathology results. A 73-year-old male patient, smoker, with a medical history of chronic obstructive pulmonary disease, presented since January 2022 with a gradual worsening of dyspnea on exertion and productive cough with weight loss. The chest X-ray detected a thoracic distention. The chest high resolution computed tomography revealed biapical subpleural parenchymatous condensations with tractive bronchiectasis and pleural retraction in the right upper lobe and diffuse bilateral cento-lobular emphysema. A scan-guided trans-parietal lung biopsy showed lung parenchyma tattooed with anthracosic deposits, largely remodeled by fibrous tissue, intermingled with numerous wavy and refractive dyselastotic structures in polarized light. The orcein staining confirmed the presence of excess elastosic fibers within these lesions. All etiological investigations were negative. His lung function studies revealed a reversible obstructive ventilatory disorder. Following a multidisciplinary discussion, the diagnosis of IPPFE was confirmed on the basis of the distribution in the upper lungs on chest computed tomography combined with pathology pattern. This case emphasizes the atypical misleading radiological presentation of IPPFE and the key role of pathological results in establishing the diagnosis. Hence, further studies are needed to improve our understanding of this uncommon disease and to establish clear-cut guidelines for IPPFE diagnosis and management.