Pulmonary alveolar proteinosis (PAP) is a rare disease characterized by a diffuse accumulation of eosinophilic periodic acid-Schiff (PAS)-positive phospholipid materials within the alveoli.

• 肺泡蛋白质沉著症为一罕见肺部疾病，其病理切片可见肺泡内有许多嗜伊红性物质沉积，且其PAS染色呈阳性。