Pulmonary Alveolar Proteinosis

**Semantic type:** Disease or Syndrome

**Definition:** A rare lung disorder characterized by the filling of the pulmonary alveoli with proteinaceous material which stains positive with periodic acid-Schiff stain. It may be idiopathic or secondary due to hematologic malignancies or the inhalation of mineral dusts. Signs and symptoms include dyspnea, cough and low grade fever.