Secondary pulmonary alveolar proteinosis complicating myelodysplastic syndrome results in worsening of prognosis: A retrospective cohort study in Japan

Secondary pulmonary alveolar proteinosis (sPAP) is a very rare lung disorder comprising approximately 10% of cases of acquired PAP. Hematological disorders are the most common underlying conditions of sPAP, of which 74% of cases demonstrate myelodysplastic syndrome (MDS). However, the impact of sPAP on the prognosis of underlying MDS remains unknown.