D103-07 Exogenous Lipoid Pneumonia Managed With Whole Lung Lavage

Abstract Introduction Exogenous lipoid pneumonia (ELP) is a rare interstitial lung disease resulting from aspiration or inhalation of lipid-containing substances such as mineral oils or petroleum-based products. Diagnosis is challenging, often mimicking infectious or inflammatory lung disease, and requires histopathologic confirmation of lipid-laden macrophages. Management involves discontinuation of exposure, corticosteroid therapy, and in severe cases whole-lung lavage (WLL) to remove accumulated lipid material. This case highlights diagnostic complexity and multidisciplinary management of ELP with organizing pneumonia. Case Presentation A 47-year-old man with chronic sinusitis on dupilumab, prior smoking (2002-2018), and vaping (2018-2024) presented with 18 months of progressive dyspnea, with his modified Medical Research Council dyspnea scale ranging from grade 2-3, and a productive cough. Pulmonary function testing showed restriction with FVC 2.41 L (43% predicted), FEV1 1.77 L (40%), and FEV1/FVC 0.80. Chest CT demonstrated diffuse centrilobular nodules, bronchial wall thickening, and ground-glass opacities. Bronchoscopy grew Haemophilus influenzae with minimal improvement after antibiotics. Persistent symptoms prompted surgical lung biopsy which revealed exogenous lipoid pneumonia with organizing pneumonia and bronchitis. Prednisone and trimethoprim-sulfamethoxazole prophylaxis provided limited improvement in clinical symptoms. He was referred to our institution for a second opinion. Extensive history revealed no obvious source for exogenous lipoid pneumonia. After risk-benefit discussion, the patient underwent sequential, bilateral WLL followed by chronic suppressive antibiotic therapy while his steroids were tapered. Patient reported immediate clinical benefit with improvement in his cough and sputum production. Follow up imaging 6 weeks after the completion of the WLL revealed significant improvement of the pulmonary infiltrates. Discussion This case highlights the diagnostic and therapeutic complexities of ELP, particularly when overlapping with recurrent bacterial infection. With vaping being the only identifiable lipid source, this case emphasizes that unrecognized exposures may occur and should not exclude ELP from the differential in compatible clinical and radiographic contexts. Though not universally established, WLL can be effective in patients with significant alveolar lipid burden, although it is most associated with alveolar proteinosis. In this case, WLL produced striking clinical improvement which adds to the limited body of evidence supporting its use in lipoid pneumonia when refractory to inciting agent removal. This case underscores the need for comprehensive assessment and individualized management in ELP and supports further research into long-term outcomes and optimal therapeutic approaches. This abstract is funded by: None