[Pulmonary alveolar proteinosis].

Pulmonary alveolar proteinosis (PAP) is a rare, diffuse pulmonary disease due to abnormal surfactant homeostasis. We present the case of a 69-year-old woman who was admitted to the hospital for progressive dyspnea with marked limitation in activity, and non-productive cough, of three months of evolution. Type I respiratory failure was confirmed. Chest tomography findings were interlobular and intralobular septal thickening, ground glass opacities and bilateral consolidation. Histological diagnosis was made and whole-lung lavage was performed with clinical improvement. We highlight the need to keep in mind differential diagnoses of respiratory failure and pulmonary infiltrates during COVID-19 pandemic, even rare entities such as PAP.