In the case of TB, pleural involvement may be in the form of pleural effusion usually in the early stages of the disease, empyema, or pleural thickening associated with calcifications and adhesions usually in chronic cases.

TB is usually the leading cause of pleural effusion in the developing countries. Tuberculous pleural fluid represents an exudate with predominant lymphocytes.

The gold standard for the diagnosis of tuberculous effusion is either:

• the detection of Mycobacterium tuberculosis in pleural fluid,
• or pleural biopsy specimens showing caseating granulomas in the pleura with acid-fast bacilli