Case Presentation:
A 65 year old Caucasian man with a history of smoking presented to the clinic with worsening cough and shortness of breath (SOB). He underwent a chest X‐ray which showed a right middle lobe infiltrate. He was treated for “walking pneumonia” with levofloxacin. His symptoms did not resolve. Subsequently, he underwent a computerized tomography (CT scan) of his chest, which revealed bilateral ground glass opacities with thickened septa. His findings were significantly greater than his clinical symptoms suggested, and he was referred to a pulmonologist. On the follow up visit, his SOB had gradually worsened and a repeat CT scan was unchanged. He underwent a transbronchial biopsy and the pathology showed pink protienecious substace positve for periodic acid schiff confirming pulmonary alveolar proteinosis (PAP). He underwent whole lung lavage (WLL) and has symptomatically improved.
Discussion:
The prevalence of acquired pulmonary alveolar proteinosis is about 1 per 100,000, and is most commonly seen in men with a smoking history. The median age of diagnosis is 39 years. It usually presents as cough with shortness of breath and sometimes expectoration. It is usually missed initially as its presentation mimics pneumonia clinically and radio‐graphically. Chest X‐ray shows bilateral perihilar infiltrates and CT scanning shows ground glass opacities with “crazy pavement” pattern. Open‐lung biopsy is the traditional confirmatory diagnostic procedure but transbronchial biopsy has become the preferred method for the diagnosis. Treatment includes whole‐lung lavage, application of granulocyte‐macrophage colony‐stimulating factor and lung transplantation. Early diagnosis and treatment can reduce 5 year mortality from up to 30% to less than 5%.
Conclusions:
Diagnosis can easily be confused with pneumonia hence physicians should have a high index of suspicion for pulmonary alveolar proteinosis especially in patients with a chronic cough with bilateral ground glass infiltrate unresponsive to antibiotics.