Alveolar proteinosis with hypersensitivity pneumonitis: a new clinical phenotype

Respirology. 2010 Nov;15(8):1197-202. doi: 10.1111/j.1440-1843.2010.01848.x.


Background and objective: The aim of the present study was to report the features of five patients with concurrent histopathological features of pulmonary alveolar proteinosis (PAP) and hypersensitivity pneumonitis (HP) and their high-resolution CT (HRCT) appearances.

Methods: Patients with histopathological features of both HP and PAP on surgical lung biopsy referred for tertiary review were retrospectively identified. The pathology and HRCT images were semi-quantitatively scored to evaluate the relative contribution to HP and PAP.

Results: Five patients had histopathological features of HP and PAP but had varied HRCT appearances. All had imaging features of PAP to a varying degree with two patients also showing characteristics of HP but three patients had ill-defined thickened interlobular septa, not typical of either disease.

Conclusions: We describe the coexistence of PAP and HP in five patients and discuss possible linkages between these two distinct pathologies.

MeSH terms

  • Adult
  • Aged
  • Alveolitis, Extrinsic Allergic / diagnostic imaging
  • Alveolitis, Extrinsic Allergic / pathology*
  • Female
  • Humans
  • Lung / diagnostic imaging
  • Lung / pathology
  • Male
  • Middle Aged
  • Pulmonary Alveolar Proteinosis / diagnostic imaging
  • Pulmonary Alveolar Proteinosis / pathology*
  • Retrospective Studies
  • Tomography, X-Ray Computed