Etiology and pleural fluid characteristics of large and massive effusion in country of high prevalence of Mycobacterium tuberculosis infection

Abstract

Study objectives It is generally thought that malignancy is the most common cause of large and massive pleural effusion. To determine the most frequent causes of large and massive pleural effusions in country of high prevalence of Mycobacterium tuberculosis infection and to compare their biochemical fluid characteristics with those of smaller size, and between tuberculous and nontuberculos conditions. Design Retrospective chart review of all patients undergoing a diagnostic thoracentesis at two university hospital in Korea, during a 2-year period. Large and massive pleural effusions were identified in 43 patients of 239 patients (18%). Results A similar etiologic spectrum between large and massive pleural effusions was observed. The most frequent cause of these pleural effusions was tuberculosis(22 patients; 51.2%), followed by parapneumonic or empyema (9 patients; 20.9%), and malignancy (5 patients; 11.6%). There was no difference in biochemical fluid characteristics between large/massive pleural effusion and nonlarge pleural effusion. However, there was a significant increase in the yield of fluid cytology in patients with large and massive pleural effusion (p<0.01). Compared with nontuberculous effusions, patients with large and massive tuberculous pleural effusion were more likely to have pleural fluid with high fraction of lymphocyte(76% vs 31%, p=0.000) and higher ADA(89.9 vs 30.8 U/L, p=0.000). Conclusions We conclude that tuberculosis is the most common cause of large and massive pleural effusion in country of high prevalence of Mycobacterium tuberculosis infection. Lymphocytic pleural effusion with high ADA favors tuberculous condition