title: Rare Presentation of Pulmonary Alveolar Proteinosis Causing Acute Respiratory Failure.
abstract: Pulmonary alveolar proteinosis (PAP) is a rare condition characterized by dysfunctional alveolar macrophages, which ineffectively clear surfactant and typically cause mild hypoxemia. Characteristic Computed Tomography findings are septal reticulations superimposed on ground-glass opacities in a crazy paving pattern, with a clear juxtaposition between affected and unaffected parenchyma. While traditionally PAP was diagnosed via biopsy, bronchoalveolar lavage (BAL) is usually sufficient; the fluid appears milky, and on microscopic examination there are foamy macrophages with eosinophilic granules and extracellular hyaline material that is Periodic Acid-Schiff positive. Standard therapy is whole lung lavage (WLL), although novel treatments are under development. The case presented is a 55-year-old woman with six months of progressive dyspnea, who developed hypoxemic respiratory failure requiring mechanical ventilation; she had typical findings of PAP on imaging and BAL. WLL was ultimately successful in restoring adequate oxygenation. Respiratory failure of this magnitude is a rare finding in PAP.
authors.affiliation: Department of Internal Medicine, Queen's University, Etherington Hall, Room 3033, 94 Stuart Street, Kingston, ON, Canada K7L 3N6.
authors.forename: Ryan R
authors.initials: RR
authors.lastname: Kroll
authors.affiliation: Trillium Health Partners-Credit Valley Hospital Site, Mississauga, ON, Canada L5M 2N1.
authors.forename: Sameer
authors.initials: S
authors.lastname: Kumar
authors.affiliation: University of Toronto, Trillium Health Partners-Credit Valley Hospital Site, Mississauga, ON, Canada L5M 2N1.
authors.forename: Ronald F
authors.initials: RF
authors.lastname: Grossman
authors.affiliation: Trillium Health Partners-Credit Valley Hospital Site, Mississauga, ON, Canada L5M 2N1.
authors.forename: Charles
authors.initials: C
authors.lastname: Price
authors.affiliation: Laboratory Medicine and Genetics Program, Trillium Health Partners-Credit Valley Hospital Site, Mississauga, ON, Canada L5M 2N1.
authors.forename: John R
authors.initials: JR
authors.lastname: Srigley
mesh_terms: D018893:Bronchoalveolar Lavage; D005260:Female; D006801:Humans; D008875:Middle Aged; D011649:Pulmonary Alveolar Proteinosis / Q000150:complications / Q000000981:diagnostic imaging* / Q000628:therapy; D013902:Radiography, Thoracic; D012131:Respiratory Insufficiency / Q000209:etiology*; D014057:Tomography, X-Ray Computed