Abstract Introduction Plastic bronchitis is a rare disorder characterized by large branching casts within the bronchial tree which cause airway obstruction and significant respiratory compromise. The pathogenesis is delineated into primary and secondary lymphatic abnormalities. The underlying cast pathology significantly impacts treatment and outcomes. Case A 49-year-old woman with a history of tobacco use disorder, reported COPD/asthma overlap, and plastic bronchitis presented to the hospital with shortness of breath and productive cough with copious amounts of rubbery white material. She was tachypneic and hypoxemic requiring endotracheal intubation due to respiratory failure. CT chest without contrast demonstrated multifocal airspace opacities. She was empirically treated with antibiotics, intravenous corticosteroids, and nebulized bronchodilators. A bronchoscopy was performed that demonstrated thick white casts causing complete obstruction of the right mainstem bronchus that were therapeutically aspirated. Pathology of these casts demonstrated histiocytes, fibrin, mucin, and hemosiderin-laden macrophages without evidence of neutrophilic inflammation or malignancy. Despite initial treatment, she developed acute respiratory distress syndrome (ARDS) due to recurrent cast formation and airway obstruction. Given the high degree of plastic casts, inhaled heparin, aggressive pulmonary hygiene, and repeat bronchoscopies were performed with eventual liberation of her endotracheal tube after improved cast clearance. For definitive treatment, a lymphangiogram with interventional radiology was performed demonstrating an abnormal terminal thoracic duct with retrograde flow into enlarged and abnormal pulmonary and mediastinal lymphatic ducts. A successful glue embolization and coiling of the thoracic duct was performed. The patient was ultimately discharged on 2 liters of supplemental oxygen, SABA/SAMA and ICS/LABA inhalers, nebulized hypertonic saline, and an airway clearance vest. Two months post-discharge she is doing well with symptomatic improvement and resolution of her cough without cast production. Discussion Plastic bronchitis is a rare, often non-diagnosed condition, that can lead to death. This case highlights the importance of studying bronchial cast pathology to identify patients who may benefit from further intervention. This patient’s cast pathology demonstrated histiocytes, fibrin, and mucin which suggests a mix of lymph and bronchial casts. This differentiates plastic bronchitis from other types of bronchial casts that have eosinophilic inflammation on pathology indicative of cast formation related to asthma or fungal hypersensitivity. In our case, the pathology resulted in expedited lymphangiogram which showed abnormal lymphatic drainage consistent with plastic bronchitis, meeting criteria for intervention with glue embolization. After lymphatic flow interruption, the patient’s symptoms and cast production improved, underscoring the importance of identifying the physiologic cause of plastic bronchitis. This abstract is funded by: None
Nollner et al. (Fri,) studied this question.