B/L Exudative pleural effusion seen in -

Ref:Robbins Basic Pathology (9th Edition), page no.511 In pleural effusion (the presence of fluid in the pleural space) the fluid can be either a transudate or an exudate. When the pleural fluid is a transudate, the condition is termed hydrothorax. Hydrothorax from CHF probably is the most common cause of fluid accumulation in the pleural cavity. An exudate, characterized by protein content greater than 2.9gm/dL and, often, inflammatory cells, suggests pleuritis. The four principal causes of pleural exudate formation are (1) microbial invasion through either direct extension of a pulmonary infection or blood-borne seeding (suppurative pleuritis or empyema); (2) cancer (lung carcinoma, metastatic neoplasms to the lung or pleural surface, mesothelioma); (3) pulmonary infarction; and (4) viral pleuritis. Other, less common causes of exudative pleural effusions are systemic lupus erythematosus, rheumatoid ahritis, and uremia, as well as previous thoracic surgery. Malignant effusions characteristically are large and frequently bloody (hemorrhagic pleuritis).