Objective: To analyze the characteristics of pathologically proved cases of cryptogenic organizing pneumonia (COP) including manifestation of CT scan, bronchoalveolar lavage (BAL) fluid cytology, pulmonary histopathological appearance.
Methods: Twenty-three consecutive patients from April 1994 to October 2005 in Peking Union Medical College Hospital with pathologic features of organizing pneumonia were enrolled in the study.
Results: Eighteen patients were diagnosed as COP. Percutaneous lung biopsy/transbronchial lung biopsy was performed in 10 patients, while open lung biopsy/video-assistant thorascopic biopsy was performed in 8 patients. There were 8 males and 10 females, aged (53.5 +/- 11.0) yr. Dyspnea, cough, inspiratory crackles were the most common symptoms and signs. Lung function tests showed a restrictive ventilatory defect (11/18), and impairment of carbon monoxide transfer factor (T(LCO), 18/18). Chest computed tomography scan in 18 cases mainly showed ground glass opacities (4/18), patchy areas of alveolar consolidation (13/18) with air bronchograms (3/18), and pleural effusion (4/18). BAL fluid cytological analysis showed the percentage of lymphocyte was 0.40 +/- 0.16, neutrophil 0.15 +/- 0.08, eosinophil 0.05 +/- 0.03; the CD(4)/CD(8) ratio was 0.43 +/- 0.21. All patients were treated with corticosteroids. Sixteen were alive and clinically improved or stabilized at the last follow up (8.7 +/- 6.2 months after diagnosis). Two patients died, one of respiratory failure, and another of pulmonary infection.
Conclusions: The diagnosis of COP is usually suggested by clinical-radiological findings, but needs to be confirmed histopathologically. The combination of BAL fluid cytological findings and lung histological appearance obtained during a bronchoscopic procedure appears to be an effective method for diagnosing this disease.