Abstract:

Objective: To explore the clinical features, diagnosis and therapy of pulmonary alveolus proteinosis（PAP）and improve
the level of clinical diagnosis and treatment to reduce misdiagnosis and incorrect treatment. Methods: Retrospective analysis of the
clinical features and chest CT data of patients with PAP in Baoshan People's Hospital in the last 9 years was made, the experience of treatment was summarized and reasons for misdiagnosis and incorrect mistreatment were analyzed. Results: Clinical symptoms were mainly polypnea and coughing after activities. And the chest high- resolution CT（HRCT）showed bilateral diffuse ground- glass opacities in 6 cases, a geographic pattern in 5 cases, a crazy paving pattern in 3 cases and air bronchogram in 2 cases. The misdiagnosis rate was high only with chest CT: 3 cases were misdiagnosed as pneumonia, 1 case as pulmonary tuberculosis and 1 case as idiopathic pulmonary interstitial fibrosis, prior to admission. 6 patients were diagnosed by bronchoalveolar lavage fluid（BALF）and transbronchial lung biopsy（TBLB）. In addition, their symptoms were markedly relived with BALF. Conclusion: Clinical manifestations of PAP were not specific, so its diagnosis was difficult and misdiagnosis and incorrect treatment were very likely if only based on HRCT. PAP should be considered when patients had polypnea and chest HRCT showed a geographic pattern and crazy paving pattern after activities. BALF was the most effective treatment. Blind treatment should be avoided when the diagnosis was not definite.

Key words: pulmonary alveolar proteinosis, transbronchial lung biopsy, bronchoalveolar lavage