Accumulation of amorphous PAS-positive material in the space between alveolar macrophages, sometimes as condensed form (oval bodies) are typically found in alveolar proteinosis. The phenotype is HP_0006517 (Intraalveolar phospholipid accumulation). Also known as: Alveolar proteinosis, Detection of PAS-positive extracellular material in broncho-alveolar lavage, Pulmonary alveolar proteinosis.