Pleural aspiration (drainage of fluid from the pleura)

The pleura makes a fluid that acts as a lubricant. Your specialist doctor may take a sample of this fluid, to see if it contains cancer cells.

What is the pleura?

The lungs are covered by a lining (membrane) called the pleura. The pleura is made up of 2 layers:

the inner layer covers the lungs
the outer layer lines the ribcage and a sheet of muscle called the diaphragm – the diaphragm separates the chest from the tummy.

The space between the 2 layers is called the pleural cavity. The pleural cavity has a small amount of fluid in it. This fluid acts as a lubricant. This allows the lungs to move in and out smoothly so you can breathe easily.

Structure of the lungs and pleura

A diagram of the lungs and pleura, showing a close-up of the inner pleura, outer pleura and the pleural cavity. — Image: The illustration shows the lungs in the chest. It shows the windpipe (trachea) coming down from the neck into the chest. About halfway down the chest, the windpipe divides into two tubes. One tube goes into the left lung. The other tube goes into the right lung. There are ribs around the outer side of each lung. Underneath the lungs, and going across the width of the body, is a muscle called the diaphragm. Surrounding each lung is a thin lining (membrane), which has two layers. This is called the pleura. The layer closest to each lung is called the inner pleura. The layer which lines the chest wall is called the outer pleura. There is a small space between the two layers of the pleura. This space is called the pleural cavity. There are groups of pea-sized lymph nodes in the chest. They are connected to each other by fine tubes. The lymph nodes are close to the windpipe. There are also lymph nodes on each side of the neck and in the shoulder area.

What is pleural aspiration?

Mesothelioma cells can cause fluid to build up between the 2 layers of the pleura around the lung. This is called a pleural effusion. Draining the fluid may help with your breathing. A specialist doctor may take a sample of this fluid to be checked for mesothelioma cells.

References

Below is a sample of the sources used in our mesothelioma cancer information. If you would like more information about the sources we use, please contact us at informationproductionteam@macmillan.org.uk

Kusamura S, Kepenekian V, Villeneuve L, Lurvink RJ, Govaerts K, De Hingh IHJT, Moran BJ, Van der Speeten K, Deraco M, Glehen O; PSOGI. Peritoneal mesothelioma: PSOGI/EURACAN clinical practice guidelines for diagnosis, treatment and follow-up. Eur J Surg Oncol. 2021 Vol, 47(1) pp6-59. [accessed April 2024].

Popat, S., Baas P., Faivre-Finn, C., Girard, N., Nicholson, A., Nowak, A., Opitz, I., Scherpereel, A, and Reck, M. 2021. ESMO Pleural mesothelioma guidelines. Malignant pleural mesothelioma: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Available from: https://www.annalsofoncology.org/action/showPdf [accessed April 2024].

Cancer Information Development team

Author

Dr David Gilligan

Reviewer

Consultant Clinical Oncologist

Addenbrookes Hospital, Cambridge

Date reviewed

Reviewed: 01 February 2025

Next review: 01 February 2028

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