PAP and CXR

 Q: 44 years old male with a history of myelodysplastic syndrome is admitted to ICU with shortness of breath. Report of Chest X-ray (CXR) from ED reads possible pulmonary alveolar proteinosis (PAP). CXR in PAP usually shows prominent air bronchograms? 

A) True 

B) False 

Answer: B 

Although the process of PAP is alveolar in distribution, air bronchograms are not seen. If air bronchograms are visible, other disease processes should be strongly considered. 

Few features of chest x-ray in PAP are bilateral symmetric alveolar opacities in a "batwing" distribution means located centrally in mid and lower lung zones. Sparing of lungs may be present by a thin lucent band sharply outlining the diaphragm and the heart. Segmental atelectasis is common due to thick lipoproteinaceous material. Patients with chronic PAP may progress towards fibrosis.

#pulmonary

References:

1. Claypool WD, Rogers RM, Matuschak GM. Update on the clinical diagnosis, management, and pathogenesis of pulmonary alveolar proteinosis (phospholipidosis). Chest 1984; 85:550. 

2. Miller PA, Ravin CE, Smith GJ, Osborne DR. Pulmonary alveolar proteinosis with interstitial involvement. AJR Am J Roentgenol 1981; 137:1069. 

3. Prakash UB, Barham SS, Carpenter HA, et al. Pulmonary alveolar phospholipoproteinosis: experience with 34 cases and a review. Mayo Clin Proc 1987; 62:499.