ETIOLOGY AND PROGNOSTIC-SIGNIFICANCE OF EOSINOPHILIC PLEURAL EFFUSIONS - A PROSPECTIVE-STUDY

Study objective: To determine the diagnostic and prognostic significan ce of eosinophilic pleural effusions. Design: A prospective cohort stu dy of patients undergoing thoracentesis between September 1990 and Sep tember 1995. Setting: A university-affiliated VA Medical Center. Patie nts: Four hundred seventy-six consecutive patients. Measurements ann r esults: Eosinophilic pleural effusions were identified in 44 of the 47 6 patients (9.2%). Malignancy was diagnosed as frequently in eosinophi lic as in noneosinophilic effusions (20.5% vs 20.1%). The only diagnos es that were significantly associated with eosinophilic effusions were idiopathic (25% vs 8%; p=0.001) and postthoracic surgery (11% vs 3%; p=0.023), Median survival was 7.7 months for those with a noneosinophi lic effusion compared to 16.8 months for those with eosinophilia (p=0. 017). This difference in survival persisted after adjustment for age a nd diagnosis. Conclusions: We conclude that malignancy is as prevalent among eosinophilic as noneosinophilic pleural effusions, However, the survival of patients with pleural fluid eosinophilia may be better th an that of patients with noneosinophilic effusions.