A Unique, Histopathologic Lesion in a Subset of Patients With Spontaneous Pneumothorax

Abstract

Context.-Spontaneous pneumothorax can be idiopathic (primary), or it can occur in association with an underlying predisposing condition (secondary). Spontaneous pneumothorax may be a harbinger of an undiagnosed clinical condition, which may be associated with serious systemic abnormalities, making early recognition and diagnosis important. The pulmonary pathology of some of these disorders has not been fully elucidated.Objective.-To review cases of pneumothorax in the hope of identifying pathologic features that might correlate to specific clinical syndromes.Design.-The pathology computer files at 3 hospitals were searched for all cases of spontaneous pneumothorax, primary and secondary, regardless of etiology during a 11-year period. Ninety-two cases were retrieved. Each of the cases was evaluated for reactive eosinophilic pleuritis, elastosis, pleural fibrosis, emphysema, intra-alveolar macrophages, cholesterol clefts, vasculopathy, and intraparenchymal or intrapleural cysts. Clinical information regarding asthma and smoking history, site of the pneumothorax, family history, radiographic findings, predisposing conditions, recurrence, age, and sex were extracted from the medical records.Results.-In 11 patients (12% of all the patients with spontaneous pneumothorax), a distinctive pattern of pleural fibrosis with islands of fibroblastic foci within a myxoid stroma was noted at the pleural-parenchymal interface or leading edge. These lesions correlated with a select subset of patients, consisting predominantly of young men.Conclusions.-Our review identified a distinct pattern of pneumothorax-associated fibroblastic lesions in a subset of cases of spontaneous pneumothorax. Whether this is related to the pathogenesis of the pneumothorax remains to be elucidated.

ERS task force statement: diagnosis and treatment of primary spontaneous pneumothorax

“…These changes visible on the visceral pleura have been called emphysema-like changes (ELCs), which are also recognised as a specific entity. Recently, in a subset of patients with spontaneous pneumothorax, fibroblastic lesions consisting of pleural fibrosis with islands of fibroblastic foci within a myxoid stroma have been described [78]. It is generally believed that pneumothorax results from the rupture of ELCs, based on a hypothesis of VANDERSCHUEREN [79], who thought that there was a continuous evolution from normal pleura to blebs and then progressive larger bullae rupturing leading to occurrence of PSP; however, this has never been proved.…”

New insights and improved strategies for the management of primary spontaneous pneumothorax

“…Over the last decades, advances in the understanding of the pathophysiology of PSP occurred mostly because of major improvements in imaging techniques (Computed tomography (CT) scan or videothoracoscopy). Subpleural blebs and bullae (BB) have been clearly described in almost all patients with PSP . These changes of the visceral pleura are referred to as emphysema‐like changes (ELC).…”

Multi-institutional retrospective cohort study of spontaneous pneumothorax

“…In accordance with its morphologic appearance and the clinical setting in which it is found, this lesion has been named pneumothorax-associated fibroblastic lesion or PAFL [11]. It consists of a triangular or wedgeshaped area of fibrosis at the pleural-subpleural interface with a gradient of dense, old fibrosis toward the pleural surface and younger, more active fibrosis with fibroblastic foci at the leading parenchymal edge.…”