Pulmonary alveolar proteinosis is a rare disease characterized by accumulation of lipoproteinaceous material in the distal airspaces. The most common form, autoimmune, is due to autoantibodies against granulocyte macrophage colony stimulating factor (GM-CSF), which impairs macrophage clearance of surfactant from alveolar spaces. Treatment for symptomatic patients includes whole lung lavage and GM-CSF augmentation therapy.