Diagnostic methods of primary tuberculous pleural effusion in a region with high prevalence of tuberculosis. A study in Mexican population.

ABSTRACT

PIP: It is often difficult to diagnose tuberculosis (TB) pleural effusion because the search for Mycobacterium tuberculosis in fluid, or the identification of historical alterations in the pleural biopsy are often false negative. The diagnosis, however, must be timely since 43-65% of patients may develop an active pulmonary TB in the next 3-5 years. To determine the age distribution of patients with pleural TB, the authors reviewed the charts of 452 consecutive inpatients from January 1991 to September 1996 hospitalized at Mexico's National Institute of Respiratory Diseases with a diagnosis of the condition. 133 patients were diagnosed with TB pleural effusion of primary origin without parenchymal abnormalities according to chest roentgenogram. These 98 men and 35 women were of mean age 42 years. Pleural granulomas were identified in 87% of subjects while fluid baciloscopy and culture were positive in only 8% and 19%, respectively. The determination of adenosine deaminase (ADA) produced a diagnostic yield of 84%. Based upon their findings, the authors stress that primary TB pleural effusion may also be seen in adults, closed pleural biopsy remains the most effective diagnostic method, and ADA level is a cheap diagnostic method in countries with a high prevalence of TB.