[Clinicopathologic features of 18 cases of cryptogenic organizing pneumonia]

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.

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.

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.

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.