Pleural fluid (pleural effusion) is an accumulation of fluid in the pleural space. The fluid compresses the lungs and disrupts its normal function. Symptoms and clinical findings vary and partially depend on the volume of the pleural effusion. Less than about 1/2 L will provide few or no symptoms.
An increase in the amount of pleural fluid can occur acutely or over a long period of time. The pleural fluid may be clear (serous) or bloody, or contain pus if infection is present. In rare cases, the fluid may be rich in fat (chylothorax). The most common causes of pleural effusion are heart failure, pneumonia, malignancy, or lung embolism.
Pleural fluid develops in almost half of all malignant tumors or metastases in the thorax. Lung cancer, breast cancer, gynecological cancer, mesothelioma, lymphoma, and leukemia often give rise to pleural fluid.
- Diagnostic—pleural effusion of unknown cause
- Therapeutic—pleural effusion sufficient to cause dyspnea
- Cytological examination of pleural fluid
- Reduce dyspnea
- Instillation of chemotherapy