Exudative Pleural Effusion Caused by Malignancy

Etiology and PathogenesisTop

Malignant pleural exudate may be caused by primary neoplasms (mesothelioma) and metastatic cancers, most often related to lung cancer, breast cancer, colon cancer, or lymphoma, although metastatic gastric, pancreatic, renal, bladder, or ovarian effusions are also encountered.

In patients with suspected malignant etiology in whom analysis of pleural fluid did not establish the diagnosis, repeat pleural fluid analysis is recommended, followed by percutaneous pleural biopsy (preferably a core-needle biopsy guided by imaging studies) if the results of testing are nondiagnostic. If the diagnosis remains in doubt, consider thoracoscopy.

TreatmentTop

Treatment is most often palliative and directed towards symptom management and management of the primary disease.

1. Asymptomatic patients with small effusions should be monitored.

2. In patients with progressive effusions, perform therapeutic thoracentesis. In almost all patients the effusion recurs after ~1 week to 1 month. Repeated thoracentesis for palliative treatment of dyspnea should be considered only in patients with a very short life expectancy.

3. In symptomatic patients with recurrent effusions, either chemical pleurodesis (pleural drainage followed by intrapleural administration of a sclerosing agent) or an indwelling intrapleural catheter can be used as the first-line definitive intervention for relieving dyspnea.

4. In symptomatic patients with unexpandable lung (see Exudative Pleural Effusion in the Course of Bacterial Pneumonia), failed pleurodesis, or loculated effusion, an indwelling intrapleural catheter is recommended.

5. Less common treatment modalities include intrapleural administration of fibrinolytic agents to facilitate drainage in patients with multiloculated pleural effusions and pleuroperitoneal shunting (in patients with lung entrapment caused by malignant infiltration).