Diagnosis of mesothelioma

Diagnosis is the process of finding out the cause of a health problem. Diagnosing mesothelioma often means first ruling out other health conditions that share similar symptoms with cancer. It can be a very worrying time for you and your loved ones. Sometimes this process is quick. Sometimes it can feel long and frustrating. But it’s important for doctors to get all the information they need before making a diagnosis of cancer.

Diagnosing mesothelioma usually begins with a visit to your family doctor. Your doctor will ask you about any symptoms you have and may do a physical exam. Based on this information, your doctor will refer you to a specialist or order tests to check for mesothelioma or other health problems.

The following tests are usually used to rule out or diagnose mesothelioma. Many of the same tests used to diagnose cancer are used to find out the stage (how far the cancer has progressed). Your doctor may also order other tests to check your general health and to help plan your treatment.

Your health history is a record of your symptoms, risks and all the medical events and problems you have had in the past. Your doctor will ask questions about your history of:

• symptoms that suggest mesothelioma
• being in contact with asbestos at work (occupational exposure)
• living with someone who works with asbestos
• previous treatment with radiation therapy to the chest or abdomen

A physical exam allows your doctor to look for any signs of mesothelioma. During a physical exam, your doctor may:

• examine the lungs using a stethoscope
• feel the abdomen for lumps or organs that are larger than normal
• look for swelling in the abdomen

Find out more about physical exams.

An x-ray uses small amounts of radiation to make an image of parts of the body on film. It is often the first imaging test used to look for problems in the chest.

A chest x-ray may show a buildup of fluid on the lungs (called pleural effusion) or a thickening of the membrane that covers each lung (called the pleura).

Find out more about x-rays.

A computed tomography (CT) scan uses special x-ray equipment to make 3D and cross-sectional images of organs, tissues, bones and blood vessels inside the body. A computer turns the images into detailed pictures.

A CT scan is the main test used to diagnose and stage pleural and peritoneal mesothelioma. Doctors use it to see where the cancer is and if it has spread. They often also use CT scans to guide them during a biopsy to take tissue samples.

Find out more about CT scans.

Magnetic resonance imaging (MRI) uses powerful magnetic forces and radiofrequency waves to make cross-sectional images of organs, tissues, bones and blood vessels. A computer turns the images into 3D pictures.

Doctors may do an MRI if the results of a CT scan are not clear. They use it to find out where mesothelioma is and how far it has spread, including if it has spread to the diaphragm.

Find out more about MRIs.

Mesothelioma can cause a buildup of fluid in the part of the body where it is growing. Doctors may remove the fluid so it can be examined in a lab to see if there are cancer cells in it.

Thoracentesis is used to test for pleural mesothelioma. The doctor passes a hollow needle through the skin, between the ribs and into the space between the lungs and the wall of the chest (called the pleural cavity). Then they use the needle to remove fluid from the pleural cavity. Find out more about thoracentesis.

Paracentesis( also called an abdominal tap) may be done as a test for peritoneal mesothelioma. The doctor passes a hollow needle or tube (catheter) through the skin and muscles into the abdominal cavity. Then they remove fluid through the needle or tube. Find out more about paracentesis.

An endoscopy is done to help diagnose and stage mesothelioma. It allows doctors to look inside the chest or abdomen using a tube with a light and camera on the end. This tool is called an endoscope. Different names are used for endoscopes depending on where they are used in the body.

Several different types of endoscopy can be used to diagnose and stage mesothelioma. Doctors may use a CT scan or an ultrasound to guide the endoscope. During the test, tissue, fluid or lymph nodes are removed so they can be examined more closely.

A thoracoscopy uses a thoracoscope to look inside the space between the lungs and the walls of the chest (called the pleural cavity). It is also used to do procedures in the chest (thoracic) cavity. Doctors use thoracoscopy to look for mesothelioma and where it may have spread. They may also use it to do a biopsy to confirm a diagnosis of mesothelioma and stage pleural mesothelioma. Find out more about a thoracoscopy.

A mediastinoscopy uses a mediastinoscope to look at the space between the lungs (called the mediastinum). It may be done if a CT scan shows that cancer may have spread to the lymph nodes between the lungs. Find out more about a mediastinoscopy.

A bronchoscopy uses a bronchoscope to look inside the windpipe (trachea) and the large airways of the lungs (bronchi). Doctors use a small ultrasound device at the end of the bronchoscope to examine the lymph nodes near these organs. If needed, doctors will use the ultrasound to guide a needle to take samples of the lymph nodes and other tissues. Find out more about a bronchoscopy.

A laparoscopy uses a laparoscope to look inside the abdomen. Doctors use it to examine the peritoneum, the diaphragm and organs in the abdomen. Find out more about a laparoscopy.

During a biopsy, the doctor removes tissues or cells from the body so they can be tested in a lab. A report from a pathologist will confirm whether or not cancer cells are found in the sample.

Different types of biopsies can be used to diagnose and stage mesothelioma. A biopsy for mesothelioma is often done during an endoscopic procedure. A CT scan or an ultrasound may be used to guide the endoscope to the area.

A needle biopsy may be used to get samples of tissue from the chest that doctors think might be cancerous. The 2 main types of needle biopsy are a fine needle aspiration and a core biopsy. Doctors use a CT scan or ultrasound to guide them during a needle biopsy. They will pass a long hollow needle through the skin in between the ribs and into the pleura. Small tissue samples can be removed through the needle. A needle biopsy may also be used to take samples from the lymph nodes in the space between the lungs (mediastinum).

A surgical biopsy may be done if doctors can’t collect enough tissue from an endoscopic procedure to make a diagnosis. To collect samples from the chest, the doctor will do a thoracotomy. They make a cut (incision) in the chest to remove tissue. To collect samples from the abdomen, doctors will do a laparotomy. They will make a cut in the abdomen to remove tissue.

Find out more about a biopsy.

Lung function tests are a group of tests that measure how well the lungs are working. They measure how much air the lungs can hold and how well the person can let air out of the lungs. Lung function tests are also called pulmonary function tests.

You may have lung function tests to see how well your lungs are working, especially if your healthcare team is thinking of offering surgery to treat mesothelioma. Part or all of a lung may have to be removed, so it’s important to make sure you are healthy enough to have and recover from surgery.

Find out more about lung function tests.

A complete blood count (CBC) measures the number and quality of white blood cells, red blood cells and platelets. A CBC is done to give your healthcare team information about your general health.

Find out more about a complete blood count (CBC).

Blood chemistry tests measure certain chemicals in the blood. They show how well certain organs are working and can help find problems.

Lactate dehydrogenase (LDH) is an enzyme that is found in cells. Higher levels of LDH may mean that there is tissue or cell damage somewhere in the body, which may be a sign of cancer. The LDH level doesn't diagnose mesothelioma, but it is used as a prognostic factor.

Find out more about blood chemistry tests.

To make the decisions that are right for you, ask your healthcare team questions about diagnosis.