Mesothelioma

What is mesothelioma?

Mesothelioma (pronounced mee-so-thee-lee-oma) is cancer of your mesothelium. Your mesothelium is a thin layer of cells that lines the outer surface of your organs, the wall of your chest and abdomen.

This information is about pleural mesothelioma, which affects the lining of your lungs. This is the most common type.

Mesothelioma is a rare cancer − about 50 people are diagnosed with it in Ireland every year.*

Mesothelioma can also develop in the lining of your abdomen, testicles or heart, but this is rare.

The layers that line your lungs (the pleura) are separated by a small amount of fluid, which helps them to slide over each other easily. This allows your lungs to get air in and out as you breathe. 

Mesothelioma causes the pleura to become hard or thicken. This makes it more difficult for your lungs to expand and contract as normal, making it harder for you to breathe. 

Sometimes fluid builds up between the two layers. This is called pleural effusion. The build-up of fluid also makes it harder to breathe, and you will feel breathless.

*The Irish Cancer Society uses the most up-to-date cancer statistics from the National Cancer Registry Ireland, available on www.ncri.ie