Learning objectives
To discuss the radiological findings of pulmonary alveolar proteinosis and its differentials.
Background
Pulmonary alveolar proteinosis (PAP) is a rare condition characterised by the accumulation of lipoproteinaceous material within the alveoli. First described in 1958, its pathophysiology was initially poorly understood with a highly variable prognosis(1). With developments in molecular genetics, however, a greater understanding of its pathogenesis has been elucidated. Acquired anti-GM-CSF antibodies which disrupt surfactant homeostasis, are the most common cause in adult cases(2). Concurrently, there were case reports of atypical forms of PAP occurring in the paediatric population. It is now known that most cases...
Imaging findings OR Procedure details
Presented here is a case of paediatric PAP in a 9-year-old male. He initially presented to his general practitioner with an 18-month history of poor weight gain, exertional chest pain and worsening dyspnoea. After a pectus carinatum deformity was noted on examination he was referred to his local paediatric hospital. A chest x-ray revealed widespread pulmonary infiltrates (Figure 1). Subsequent CT chest (Figure 2) showed interstitial and alveolar pulmonary infiltrates throughout the right upper, middle and lower lobes and left upper lobe with ground glass...
Conclusion
PAP is a rare condition that should be considered in the differential for "crazy paving" pattern on CT chest.
References
Rosen, SH, Castleman, B, Liebow, AA. Pulmonary alveolar proteinosis. New England Journal of Medicine. 1958 June; Volume 258(No 23): p. 1123-1142.
Kumar A, Abdelmalak B, Inoue Y, Culver DA. Pulmonary alveolar proteinosis in adults: pathophysiology and clinical approach. Lancet Respiratory Medicine. 2018; Volume 6(No 7): p. 554-565.
Bush A, Pabary R. Pulmonary alveolar proteinosis in children. Breathe. 2020; Volume 16(No 2): p. 200001.