Tests for mesothelioma

Mesothelioma usually starts in the pleura Open a glossary item. This is called pleural mesothelioma. More rarely it can start in the peritoneum Open a glossary item. This is called peritoneal mesothelioma.  

The tests you have depend on your symptoms. If you are diagnosed with mesothelioma it also depends on whether it is in the lining of your lungs or abdomen.  

You usually have several tests. These might include some of the following:

  • an x-ray
  • a CT scan
  • draining fluid to look for cancer cells
  • thoracoscopy Open a glossary item and biopsy Open a glossary item
  • laparoscopy Open a glossary item and biopsy
  • ultrasound scans

Tests your GP might do

Most people start by seeing their GP. They can do some tests to help them decide whether you need a referral to a specialist. Your GP might send you for an x-ray.

X-rays use high energy rays to take pictures of the inside of your body. If you have symptoms that could be caused by mesothelioma, your doctor will arrange for you to have an x-ray.

A chest x-ray can show up fluid collecting in the lining of your lung (the pleura). It can also show up cancer in the lung.

An x-ray of your tummy (abdomen) might show up a swelling or fluid collecting in the tummy. Usually, you also need an ultrasound of your tummy.

Tests your specialist might do

Depending on the results of your x-ray, your GP might refer you to a specialist.

You might see:

  • a doctor specialising in breathing problems (respiratory specialist) if you have lung symptoms
  • a doctor who treats digestive disorders (gastroenterologist) if you have abdominal symptoms

The specialist doctors usually do all the necessary tests until you have a diagnosis.

If it is mesothelioma, and it can’t be removed with surgery, they will refer you to a medical oncologist. This is a doctor who specialises in cancer.

The tests the specialists might do include: 

  • CT scan
  • draining fluid from your lung or abdomen
  • ultrasound scan Open a glossary item
  • PET-CT scan
  • thoracoscopy and biopsy
  • bronchoscopy and endoscopic ultrasound
  • mediastinoscopy
  • endoscopic ultrasound
  • laparoscopy and biopsy

CT scan

A CT scan is a test that uses x-rays and a computer to create detailed pictures of the inside of your body. It takes pictures from different angles. The computer puts them together to make a 3 dimensional (3D) image. CT (or CAT) stands for computed (axial) tomography.

Doctors can use a CT scan to look for mesothelioma. It can show abnormal swellings in the lining of your lungs (pleura) or abdomen (peritoneum).

Draining fluid from your lung or abdomen

Cancer cells can inflame the lung lining (pleura) or abdominal lining (peritoneum). This can cause fluid to build up.

Fluid around the lungs is called a pleural effusion. Fluid in the abdomen is called peritoneal ascites. The doctors can drain the fluid to see if it contains cancer cells.

To drain the fluid, your doctor will give you a small injection of local anaesthetic into the area where they want to drain the fluid. They then put a small tube (a catheter) using a needle into the chest or abdomen.

Ultrasound scan

Ultrasound scans use high frequency sound waves to create a picture of a part of the body. 

You might have an ultrasound scan of your chest or abdomen to check for mesothelioma. The scan shows up blood flow and changes, including abnormal growths.

PET-CT scan

A PET-CT scan combines a CT scan and a PET scan. PET stands for positron emission tomography. The PET scan uses a mildly radioactive drug to show up areas of your body where cells are more active than normal.

The CT scan takes a series of x-rays from all around your body. The computer puts them together to create a 3 dimensional (3D) picture.

Not everyone needs a PET-CT scan. Your doctors might organise one if it is difficult to diagnose your mesothelioma with other tests.

Other tests for pleural mesothelioma

Thoracoscopy and pleural biopsy

You might have a thoracoscopy to check for signs of mesothelioma in your lungs. It is a small operation.

Your doctor makes a small cut (incision) in the inside of your chest between 2 ribs. They put a flexible tube with a light and video camera attached through the cut. This is called a thoracoscope. They use it to take samples (biopsies) from the tissues that cover your lung (pleura).

You might have this small operation under a general anaesthetic Open a glossary item. Or you might have a local anaesthetic Open a glossary item and a medicine to make you drowsy (sedation).

Endobronchial ultrasound (EBUS)

Endobronchial ultrasound is also called Endobronchial Ultrasound-guided Transbronchial Needle Aspiration (EBUS-TBNA).

This test uses a narrow flexible tube to look at the inside of the breathing tubes (airways) in your lungs. The tube has an ultrasound probe. It uses high frequency sound waves to create pictures of the lung and pleura and also the nearby lymph glands. Open a glossary item

Your doctor can see any areas that look abnormal and take samples (biopsies) to test.

For the test your doctor puts a flexible tube called a bronchoscope into your mouth and down your airway. You have sedation and a throat spray before you swallow the tube. Some people have it under a general anaesthetic.

This test can show if an abnormal looking area is mesothelioma and the size of the tumour. It can also show if the cancer has spread into other areas of the lung or nearby lymph glands.


Mediastinoscopy is a test where your doctor makes a small cut at the lower part of your neck. They then put a long, thin, flexible tube called a mediastinoscope through the cut and into the mediastinum. The mediastinum is the centre of your chest. It includes the area between your lungs. It contains:

  • the heart
  • the main blood vessels
  • lymph glands
  • the food pipe (oesophagus)

A camera at the end of the tube connects to a large screen so the doctor can see pictures of the inside of your chest. They can examine the area between your lungs and take biopsies if they need to.

You might have this test to see if cancer cells have spread into the lymph nodes around your windpipe.

You have this test under a general anaesthetic.

Endoscopic ultrasound

An endoscopic ultrasound (EUS) combines ultrasound and endoscopy to look at the areas around your food pipe.

An endoscopy is a test to look inside your body. Your doctor uses a long flexible tube, called an endoscope. For the test your doctor puts the endoscope into your mouth, down your throat into your food pipe. You have sedation or a throat spray before you swallow the tube. 

The endoscope has a tiny camera and light on the end and an ultrasound probe attached.

The ultrasound scan uses high frequency sound waves to create a picture of the inside of your body.

An endoscopic ultrasound can check whether cancer has spread into the lymph nodes in the centre of the chest close to the windpipe. The doctor can also take tissue samples (biopsies) of enlarged lymph nodes or abnormal looking pleural tissue.

Other tests for peritoneal mesothelioma

Laparoscopy and biopsy

A laparoscopy is a small operation to look inside your abdomen. The doctors look for signs of cancer. It is also called keyhole surgery.

The doctor uses a tube with a camera and light attached. This is called a laparoscope. They make several small cuts in your abdomen. They put the laparoscope through one of the cuts and into your abdomen. They also pass a tool through to take biopsies from any abnormal looking areas in your abdomen. The doctor may use either an ultrasound or CT scan for guidance. 


The tests you have helps your doctor find out if you have mesothelioma and how far it has grown.

This is important because doctors plan your treatment according to the stage of the cancer.

Coping with mesothelioma

Coping with a diagnosis of mesothelioma can be difficult. There is help and support available to you and your family

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  • Initial management of malignant pleural mesothelioma
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  • Peritoneal mesothelioma: PSOGI/EURACAN clinical practice guidelines for diagnosis, treatment and follow-up 
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Last reviewed: 
30 Jun 2023
Next review due: 
30 Jun 2026

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