Coexisting endogenous and exogenous lipoid pneumonia and pulmonary alveolar proteinosis in a patient with...

We report a unique case of coexisting exogenous lipoid pneumonia, endogenous lipoid pneumonia (ELP), and pulmonary alveolar proteinosis (PAP) in a 5-year-old patient with severe neurodevelopmental disease. The patient presented with gastroesophageal reflux and presumed chronic lung disease resulting from recurrent aspiration pneumonias and succumbed to respiratory failure. The autopsy showed lipid-laden macrophages and periodic acid-Schiff-positive granular material in alveolar spaces and multilamellated structures within both alveolar macrophages and extracellular debris. These findings were similar to those in previous reports of coexisting ELP and PAP in the setting of gastroesophageal reflux. However, the present case differed by the presence of scattered large osmiophilic extracellular lipid vacuoles. Besides strengthening the association between ELP and PAP and their relationship to gastroesophageal reflux, this case suggests that they may arise together with exogenous lipoid pneumonia, through related mechanisms, in the setting of neurodevelopmental disease.