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Chest radiograph: Diffuse bilateral ill-defined airspace opacities are seen in a variable distribution.
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Chest CT: CT demonstrates diffuse bilateral ground-glass opacities with superimposed interlobular septal thickening in a “crazy paving” pattern with regions of geographic sparing.
Differential diagnosis
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Pulmonary alveolar proteinosis
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Acute respiratory distress syndrome (ARDS)
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Severe pulmonary edema
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Diffuse alveolar hemorrhage
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Pneumocystis jirovecii infection
Diagnosis: Pulmonary alveolar proteinosis
The patient underwent bronchoalveolar lavage, which demonstrated milky and turbid fluid with thick sediment. Cytology demonstrated large foamy macrophages. Serum antigranulocyte-macrophage colony-stimulating factor (anti-GM-CSF) autoantibodies were positive.
