SHM Converge Scientific Abstract ePoster Gallery-Clues in the Crackles: The Case of Pulmonary Alveolar Proteinosis

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This case describes a 17-year-old previously healthy girl with one month of progressive cough and exertional dyspnea. She had normal vital signs, faint bilateral crackles, recent weight loss, and unremarkable inflammatory and laboratory studies. Chest imaging showed diffuse bilateral air-space consolidations on CXR and extensive ground-glass opacities with interstitial thickening on CTA.  <br /><br />She was initially treated empirically for atypical pneumonia, but the clinical course did not fit an acute infection, so antibiotics were stopped. Pulmonology recommended bronchoscopy with bronchoalveolar lavage (BAL). BAL showed normal mucosa with mild friability, and cytology later demonstrated foamy, lipid-laden macrophages with PAS-positive granular cytoplasm and extracellular proteinaceous globules, confirming pulmonary alveolar proteinosis (PAP). A subsequent video-assisted thoracoscopic biopsy showed anti–GM-CSF antibody–negative disease, consistent with non-autoimmune PAP.  <br /><br />The discussion highlights that PAP is a rare disorder caused by impaired surfactant clearance and accumulation of lipoproteinaceous material in the alveoli. It can be congenital, autoimmune, or secondary to environmental, infectious, or malignant causes. Classic imaging includes bilateral ground-glass opacities, and BAL typically reveals PAS-positive material. Autoimmune PAP is associated with circulating anti–GM-CSF antibodies, whereas congenital and secondary forms are antibody-negative.  <br /><br />The case emphasizes the diagnostic challenge of distinguishing PAP from more common causes of chronic cough in adolescents, such as atypical pneumonia or hypersensitivity pneumonitis. The authors stress that persistent respiratory symptoms with incongruent infectious findings should prompt a broader differential, including interstitial lung disease and surfactant-clearance disorders. Early specialist involvement, advanced imaging, and tissue/fluid sampling were key to diagnosis, and maintaining diagnostic openness helped avoid anchoring bias and unnecessary treatment.

Asset Subtitle

Krishna Trivedi

Meta Tag

Author List Krishna Trivedi, Laura Carter, Zoe Listernick

Category Clinical Vignettes

Concept Pulmonary Alveolar Proteinosis

Concept Surfactant Clearance

Concept Intra-alveolar Accumulation

Concept Lipoproteinaceous Material

Concept Anti-GM-CSF Antibodies

Distinguished Finalist

Presenter Organization Northwestern University - Lurie Children's Hospital of Chicago

Presenting Author Krishna Trivedi

Track Pediatric

Keywords

pulmonary alveolar proteinosis

PAP

ground-glass opacities

bronchoalveolar lavage

PAS-positive macrophages

lipid-laden macrophages

non-autoimmune PAP

anti-GM-CSF antibody negative

interstitial lung disease

chronic cough adolescent

Pulmonary Alveolar Proteinosis

Surfactant Clearance

Intra-alveolar Accumulation

Lipoproteinaceous Material

Anti-GM-CSF Antibodies