Clinical features of secondary pulmonary alveolar proteinosis associated with myelodysplastic syndrome: Two case reports.

RATIONALE

Pulmonary alveolar proteinosis (PAP) is a rare lung disorder characterized by the abnormal accumulation of alveolar surfactant protein in alveolar spaces. Secondary PAP can result from myelodysplastic syndrome (MDS).

PATIENT CONCERNS

But most reports described a single case; here we reported 2 cases of PAP secondary to MDS. One case developed secondary PAP at the same time as MDS, and the other developed during the course of MDS.

DIAGNOSES

The diagnosis of PAP was made by bronchoalveolar lavage and based on the identification of periodic acid-Schiff-positive proteinaceous material. Chest high resolution CT (HRCT) scans showed variable distribution of ground glass opacities, but crazy-paving appearance was not seen in our 2 cases.

INTERVENTIONS

Because the patients' general conditions were poor, whole lung lavage was not used in the 2 cases.

OUTCOMES

And the 2 cases' prognoses were poor.

LESSONS

In conclusion, pulmonary physicians should suspect the possibility of secondary PAP when they encounter unexplained pulmonary infiltrates with some hematologic or infectious disease that shows diffuse bilateral GGO on an HRCT scan.