The First Case of Pulmonary Alveolar Proteinosis With Small Cell Lung Carcinoma.

Pulmonary alveolar proteinosis (PAP) is a rare pulmonary disease characterized by alveolar accumulation of surfactant lipids and proteins. It is usually autoimmune and secondary to hematologic malignancy or infection. To date, only 5 case reports of PAP associated with lung cancers, including 2 cases of squamous cell carcinoma and 3 cases of adenocarcinoma, have been published. To the best of our knowledge, no case of PAP with small cell lung carcinoma has been reported thus far. We herein report the first case of PAP associated with small cell lung carcinoma.