Pulmonary alveolar proteinosis in a patient with acute lymphoid leukemia regression after G-CSF therapy

Pulmonary alveolar proteinosis (PAP) is the intra-alveolar accumulation of periodic-acid schiff (PAS) positive material. PAP is one of the underrecognized causes of pulmonary infiltrates in patients with hematologic malignancies. Here, we present a patient with acute lymphoid leukemia (ALL) in first remission that developed fever and diffuse pulmonary infiltrates during the neutropenic stage of consolidation chemotherapy. The histopathologic examination of bronchoalveolar lavage (BAL) fluid and transbronchial biopsy specimen demonstrated the presence of PAS-positive eosinophilic material. Empirical antibiotherapy and granulocyte-colony stimulating factor (G-CSF) were given. After the correction of neutropenia with G-CSF, the patient's fever disappeared, acute phase reactants decreased, pulmonary infiltrates resolved. We present this case because it was the first patient in whom the correction of neutropenia with G-CSF was followed by resolution of PAP.