Causes of pleural exudates in a region with a high incidence of tuberculosis

OBJECTIVE: To define the causes of exudative pleural effusions in our region. METHODOLOGY: A retrospective study was performed on consecutive patients with exudative pleural effusion seen in our hospital during a 4-year period. RESULTS: Of 186 patients with a mean age (+/- SD) of 51.2 (+/- 19.2) years with exudative pleural effusions, 131 (70.4%) were males and 55 (29.6%) were females. The most frequent cause of exudative pleural effusions was tuberculosis (44.1%), followed by malignancy (29.6%). The majority (94.5%) of malignant pleural effusions were due to lung cancer. Apart from a patient with bilateral pleural effusions due to cryptococcosis, patients with tuberculous pleural effusion (mean age (+/- SD), 39.7 (+/- 17.5)) were significantly younger than the rest (P < 0.05). Tuberculous effusions were most frequent in the first five decades (60/82, 73.2%) and were the most common type of pleural effusion, accounting for 60 (69.8%) of 86 cases, in this age range. Malignant effusions were more frequent among the older age groups, 74.5% (41/55) of patients with malignant effusions being older than 50 years. Most types of pleural effusions showed a preference for the right side. Of the 44 cases of large effusions, 28 (63.6%) were caused by malignancy. CONCLUSIONS: In our region with a high incidence of tuberculosis, the most frequent cause of pleural exudates is tuberculosis followed by malignancy, particularly lung cancer.