Pleuroparenchymal fibroelastosis secondary to autologous hematopoietic stem cell transplantation: A case report

Pleuroparenchymal fibroelastosis (PPFE) is a rare interstitial lung disease. Although an increased number of PPFE cases have been reported recently, the characteristics of this condition have not been well described. The present study reports on the case of a 34-year-old male patient who presented with unilateral lung abnormalities. The patient was admitted due to a 9-year history of progressive cough and exertional dyspnea, as well as a history of Hodgkin's lymphoma treated by autologous hematopoietic stem cell transplantation (HSCT). The patient had been initially diagnosed with tuberculosis and received regular anti-tuberculosis therapy for 18 months; however, the symptoms progressed. Serial chest computed tomography scans indicated a gradually worsening diffuse pleural thickening, dense subpleural opacification and volume loss, associated with evidence of fibrosis in the right lung. On physical examination the patient was cachectic, with a body mass index of 18.5 kg/m², and he had a flattened thoracic cage. Arterial blood gas analysis revealed hypoxia. Pulmonary function tests revealed restrictive ventilation dysfunction and decreased diffusion capacity. The microbiological and cytological examinations were negative. Lung biopsy revealed a thickened pleura consisting of large amounts of collagen and elastic fibers, coexisting with subpleural intra-alveolar fibrosis with alveolar septal elastosis, without inflammatory infiltrates. The patient was diagnosed with PPFE secondary to HSCT and eventually succumbed to respiratory failure and infection while waiting for a lung transplant. Physicians should be aware of the typical and atypical characteristics of this rare disease, as its clinical and radiological characteristics may lead to misdiagnosis, particularly as chronic infections. The prognosis remains poor without effective long-term treatment.