Pleural fluid is the fluid that surrounds the lungs and lubricates their linings. Removing and examining a sample of pleural fluid can help identify infection or cancer cells if they are present in the pleural fluid.
Removing and examining a sample of pleural fluid is commonly performed when an abnormally increased amount of pleural fluid is present. It can help determine if cancer or infection is the cause of the increased fluid.
In this test, the skin over an area of the lungs is cleaned with an antiseptic. The area is then numbed with a local anesthetic. After the skin is numb, a needle is passed through the skin and into the space surrounding the lungs. A small volume of fluid is taken out and sent to the laboratory. A microscope is then used to examine any cells that are in the fluid. The fluid may also be evaluated for infection by culturing the fluid to see if bacteria or fungi are present.
Normally, no preparation is required for this test.
Malignant cells, bacteria or fungi are not normally present in pleural fluid. If cancerous cells are found, a malignant tumor is present. This tumor could be lung cancer, breast cancer, non-Hodgkins lymphoma, or any other cancer that has spread to the lungs from somewhere else in the body. If there are bacteria or fungi in the fluid, then those infections should be treated.