Acute respiratory failure caused by secondary alveolar proteinosis in a patient with acute myeloid leukemia: a case report

Pulmonary alveolar proteinosis (PAP) is a rare cause of chronic respiratory failure due to progressive alveolar accumulation of a periodic acid-schiff (PAS) positive proteinaceous material. In some cases, the rapid accumulation of in tra-alveolar material leads to acute respiratory failure (ARF). We report the causative role of secondary PAP in the case of a 26-year-old man with acute myeloid leukemia who developed fever, increased serum lactate deshydrogenase level and ARF, and required mechanical ventilation. The diagnosis of PAP was established by the examination of material obtained by bronchoalveolar lavage (BAL). Respiratory improvement occurred several days after the patient had recovered from neutropenia. This report underlines the importance of the early diagnosis of PAP as a potential cause of ARF in leukemic patients. Adequate stain on BAL fluid provides the diagnosis and avoids repeated invasive procedures and inappropriate treatments.