[Clinical characteristics of fibrosing mediastinitis complicated with pleural effusion].

Objective: To characterize the clinical presentation and radiographic features of fibrosing mediastinitis (FM) patients with concomitant pleural effusion. Methods: We conducted a retrospective analysis of 24 FM patients diagnosed at West China Hospital between August 2019 and December 2023. Participants were stratified into pleural effusion and non-pleural effusion groups. Clinical data including symptoms, pleural fluid analysis, echocardiography, chest CT, bronchoscopy, and histopathological findings were systematically evaluated. Results: The cohort (mean age 58±13 years) predominantly presented with cough, dyspnea, and hemoptysis. Pleural effusion was identified in 79.2% (19/24) of cases, with 73.3% (11/15) being transudative. Pulmonary hypertension was observed in 20.8% (5/24) of patients. CT imaging revealed: bronchial stenosis (54.2%, 13/24), pulmonary artery stenosis (58.3%, 14/24), pulmonary vein stenosis (79.2%, 19/24), and superior vena cava stenosis (8.3%, 2/24). Notably, pulmonary vein stenosis occurred significantly more frequently in pleural effusion patients (89.5% vs 40.0%, P<0.05). Bronchoscopic findings demonstrated bronchial stenosis (70%) and characteristic carbonaceous deposits (100%). Histopathological examination consistently showed fibrous tissue proliferation, carbon deposition, and lymphocytic infiltration. Conclusions: FM primarily affects middle-aged and elderly individuals, presenting with non-specific respiratory symptoms. Pleural effusion represents a common complication, typically transudative in nature. Our findings suggest that pulmonary venous stenosis may play a pivotal role in the pathogenesis of pleural effusion in FM patients.