Mesothelioma diagnosis
How mesothelioma is diagnosed
If you have symptoms of mesothelioma, you usually begin by visiting your GP. They will ask you about your symptoms and examine you. They may also ask if you have been exposed to asbestos in the past. You may have blood tests and a chest x-ray.
Depending on the results, your GP may refer you to hospital for further tests. At the hospital, you will see a specialist doctor. They will ask you about your general health and any previous medical problems.
The specialist may ask if you have been exposed to asbestos in the past. This might include jobs you have had or places you have worked. They may also ask if anyone in your family worked with asbestos. It usually takes a long time for mesothelioma to develop after exposure to asbestos. You may have to think back to your childhood or early working years.
Related pages
Tests for pleural mesothelioma
Pleural mesothelioma often starts as tiny lumps (nodules) in the pleura. These will not show up on x-rays or scans until they are quite large.
If fluid has developed between the 2 layers of the pleura (pleural effusion), this usually shows up on a chest x-ray at an earlier stage. A pleural effusion can also develop because of other cancers and some non-cancerous conditions.
You may need to have a few different tests before your doctors can make a diagnosis. Your doctor or nurse will tell you about the most suitable tests for you and what they involve.
Chest x-ray
CT scan
A CT scan makes a detailed picture of the inside of the body. The picture is built up using x-rays taken by the CT scanner. The scan uses radiation, but this is very unlikely to harm you. It will not harm anyone you come into contact with.
You have the scan at a hospital. You will get an appointment letter explaining whether you need to do anything before the scan. You should tell the person doing the scan if you are pregnant or think you could be.
You may have a drink or injection of a dye. This is called a contrast. It helps show certain areas of the body more clearly. The contrast may make you feel hot all over for a few minutes. It is important to tell your doctor if you are allergic to iodine or have asthma. This is because you could have a more serious reaction.
The scan is painless. It usually takes 5 to 10 minutes. The scanner looks like a large, thick ring. You lie still on a narrow bed which moves slowly backwards and forwards through the ring.
Pleural biopsy
During a biopsy, the doctor may remove a small piece of tissue so it can be looked at under a microscope. They may suggest a biopsy of the thickened pleura.
A pleural biopsy is more likely to confirm mesothelioma than a sample of fluid. A pleural biopsy can be taken in different ways.
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CT or ultrasound guided biopsy
A specialist doctor will give you a local anaesthetic to numb the area. They use an ultrasound or CT scan to help guide them to the right place. They pass a special type of needle through your skin into the thickened area. The needle has a tip that can cut out a small sample of tissue.
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Thoracoscopy
The doctor uses a thin tube (thoracoscope) to look at the pleura and the area around the lungs. They may also take biopsies.
You will have either a general anaesthetic, or a local anaesthetic with a sedative to make you sleepy. The specialist doctor makes a small cut in your chest wall. They then put the thoracoscope into your chest. The tube has a light and camera at the end, so the doctor can see into your chest. The doctor then drains any fluid and takes a biopsy.
Sometimes the doctor uses a video camera with the thoracoscope when taking biopsies. This is called video-assisted thoracoscopic surgery (VATS). It can help the doctor see the area around the lung more clearly and, if needed, do complex operations.
Draining fluid from the pleura (pleural aspiration)
Talc pleurodesis
After draining fluid or taking a biopsy, the doctor may put a sterile, medical grade talcum powder (talc) between the layers of the pleura. This helps prevent the fluid coming back. This is called talc pleurodesis. They put the talc through the tube in your chest and into the pleural space. This helps stick the 2 linings together, to help stop the fluid building up again.
A small, rubber tube may be left in place in your chest to drain any fluid and help your lung expand. This tube is usually removed after a few days.
If your lung does not expand, doctors might leave a small tube inside the space between the pleura. It is about the size of a straw and is called an indwelling pleural catheter (IPC). You can open it at home to drain the fluid and prevent breathlessness.
Tests on the lymph nodes around the lungs
Tumour markers
Tests for peritoneal mesothelioma
You may have several different tests to help diagnose peritoneal mesothelioma.
CT scan
MRI scan
Draining fluid from the abdomen (peritoneal aspiration)
Mesothelioma cells can cause fluid to collect in the abdomen. This is called ascites. Your doctor may take a sample of this fluid to send to the laboratory. This is to see if it contains mesothelioma cells.
You may have an ultrasound scan during the test. Ultrasound uses sound waves to build up a picture of the area. This helps guide the doctor to where the fluid is. Your doctor will give you a local anaesthetic to numb the area first. After this, they pass a needle through your skin into the fluid to take a sample.
Peritoneal biopsy
During a biopsy, a small piece of tissue is removed so that it can be looked at under a microscope. Your doctor may suggest a biopsy of the peritoneum (lining that covers the organs in the tummy) to help diagnose peritoneal mesothelioma. It can be done in 2 ways.
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Laparoscopy (keyhole surgery)
A laparoscopy allows the doctor to look at other areas in your tummy (abdomen) and take more biopsies if needed. It is done under general anaesthetic. Your doctor will make a small cut in the tummy wall. They will put a thin tube with a light and camera at the end (laparoscope) into your tummy. They can then take a small biopsy of the peritoneum. They will also check nearby organs to see if the mesothelioma has spread.
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CT or ultrasound guided biopsy
The doctor will give you a local anaesthetic to numb the area. They use an ultrasound or a CT scan to help guide them to the right place. They pass a special type of needle through your skin into the area they want to take a biopsy from. The needle has a tip that can cut out a small sample of tissue.
After a peritoneal biopsy
Having a biopsy can be uncomfortable but should not be painful. If you have any pain during or after the procedure, tell your doctor or nurse.
After the doctor has taken the biopsy, they will send it to the laboratory. A doctor who looks at cells or body tissue under a microscope to diagnose cancer (pathologist) will look at the biopsy.
Sometimes, even after taking a biopsy the doctors may not be sure of the diagnosis. This is because it can be difficult to find the difference between mesothelioma and some other cancers and illnesses. If this happens, the samples may be sent to specialist laboratories to confirm the diagnosis. Sometimes you may need to have a test done again, or you may be referred to another hospital for a second opinion.
About our information
This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer.
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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].
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