Fluid Around the Lungs (Malignant Pleural Effusion), ASCO's curriculum

This section has been reviewed and approved by the PLWC Editorial Board, 05/05

A pleural effusion is a condition where extra fluid builds up in the pleural space, which is the space between the edge of the lungs and the chest wall. A malignant pleural effusion is caused by cancer that grows in the pleural space. About half of people with cancer develop a pleural effusion. More than 75% of people with a malignant pleural effusion have lymphoma or cancers of the breast, lung, or ovary.


People with a pleural effusion may experience the following symptoms:

  • Dyspnea (shortness of breath)
  • Dry cough
  • Pain
  • Feeling of chest heaviness
  • Inability to exercise
  • Malaise (feeling unwell)


The following tests may help diagnose a malignant pleural effusion, determine the exact location of the pleural effusion, or plan treatment:

  • A physical examination
  • Chest x-ray (a picture of the inside of the body), which show the buildup of fluid
  • Computerized tomography (CT or CAT) scan (an imaging test that creates a three-dimensional picture of the inside of the body with an x-ray machine)
  • Ultrasound (an imaging test that uses sound waves to create a picture of the inside of the body)
  • Thoracentesis (the removal and analysis of fluid from the pleural cavity with a needle)


A pleural effusion may require treatment in a hospital. The most common treatment is to drain the malignant pleural fluid. This may be done in several ways:

  • Thoracentesis
  • Tube thoracostomy (insertion of a tube in the chest) for about 24 hours followed by pleurodesis (a process in which substances, such as talc, are used to try to get the edge of the lung to stick to the chest wall to decrease the chance of the fluid returning)
  • The insertion of a port, catheter (a small tube placed into a vein temporarily), or shunt (a device used to bypass or divert fluid from one place to another) to drain excess fluid.

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