Intermediate magnification micrograph of<unk> . H&E stain. The diagnosis of<unk>  is made using a combination of a person's symptoms, chest imaging, and microscopic evaluation of lung washing/tissue. Additional testing for serum anti-GM-CSF antibodies are helpful for confirmation. Although both the symptoms and imaging findings are stereotypical and well-described, they are non-specific and indistinguishable from many other conditions. For example, chest x-ray may show<unk>  opacities, and a CT may show a crazy paving lung pattern, both of which are seen more commonly in numerous other conditions. Thus, the diagnosis primarily depends on the pathology findings. Lung washings or tissue for histopathologic analysis are most commonly obtained using bronchoalveolar lavage and/or lung biopsy. Characteristic biopsy findings show filling of the alveoli (and sometimes terminal bronchioles) with an amorphous eosinophilic material, which stains strongly positive on PAS stain and the PAS diastase stain. The surrounding alveoli and pulmonary interstitium remain relatively normal. Electron microscopy of the sample, although not typically performed due to impracticality, shows lamellated bodies representing surfactant. An alternative diagnosis with similar histomorphologic findings is Pneumocystis jirovicii pneumonia. Lung washings characteristically yield a fluid which is "milky"composition. Under the microscope, samples show 20-50 micrometer PAS-positive globules on a background of finely granular or amorphous PAS-positive material. There is typically a low numbers of macrophages and inflammatory cells (although this is variable).
Pulmonary alveolar proteinosis
Cryptogenic organizing pneumonia
Eosinophilic pneumonia
Lipid pneumonia
Acute eosinophilic pneumonia
Parasitic pneumonia
Pulmonary sequestration
Pulmonary alveolar microlithiasis