Understanding a Mesothelioma Diagnosis
When diagnosing mesothelioma, doctors follow steps that allow them to gather information about the disease.
Diagnostic tests like biopsies and imaging scans help doctors learn the following about a patient’s disease.
- Location: Pleural (chest), peritoneal (abdomen) or pericardial (heart)
- Cell Type: Epithelioid (most common), sarcomatoid (least common) or biphasic (mixed cell type)
- Stage: Stages 1-4, where 1 is the least advanced and 4 is the most advanced (used only for pleural mesothelioma diagnoses)
Steps of a Mesothelioma Diagnosis
Patients initiate the diagnosis process when they report to a doctor their possible mesothelioma symptoms. From there, doctors order a series of tests to assess what is causing the symptoms. If doctors suspect mesothelioma, they will take samples of cells to analyze. A cell sample is necessary to confirm a diagnosis.
Here is what to expect from each mesothelioma diagnosis step:
1. Doctor Examination
Doctors first review your symptoms and perform a physical examination of your chest and abdomen. If symptoms are congruent with mesothelioma, doctors will ask about your medical and personal history. This helps them to determine your individual risk factors for mesothelioma.
In this stage, it is vital to tell your doctor about your past asbestos exposure since this is the top risk factor for developing mesothelioma. You should also be prepared to tell your doctor about when your symptoms started and whether they have worsened.
2. Imaging Tests
If doctors suspect mesothelioma after they have conducted a physical exam, they will order imaging tests. Different imaging tests tell doctors different things about your symptoms and the possible causes.
Types of imaging tests include:
- Chest X-Rays: Doctors order chest X-rays when patients have symptoms like a cough and shortness of breath. Chest X-rays can reveal things like thickening or plaques in the pleura (lung lining), fluid buildup in the chest wall and between the lungs or changes to the lungs typical of asbestos exposure.
- CT Scans: CT scanners rotate around your body taking multiple pictures. Doctors use CT scans to determine the exact location of tumors and where they have spread to. This helps them understand how localized the tumors are and if surgery is an option.
- PET Scans: Positron emission tomography (PET) scans help doctors determine if the abnormal growths identified during examination and other tests may be cancerous. Doctors inject a radioactive substance into the blood, revealing whether it is cancer cells that absorb the substance.
- MRI: Magnetic resonance imaging (MRI) scans use magnets instead of X-rays. MRIs help doctors locate tumors and see if they have spread to other organs such as the diaphragm.
- Echocardiogram: An echocardiogram is another test sometimes used to help identify fluid buildup in the heart lining (the pericardium). Mesothelioma can originate in the heart lining or it can spread to the heart lining from another location. Echocardiograms and other tests together can determine one of these possibilities.
The final step in diagnosing mesothelioma is to collect sample cells from the tumors. The imaging tests conducted in step 2 help doctors determine where to take the samples from.
The procedure used for collecting tissue samples from tumors is called a biopsy.
Biopsies can be done in the following ways:
- Needle Biopsies: Long, thin needles extract small samples of tumor tissue from the chest. Needle biopsies are also sometimes used to take samples from lymph nodes to confirm whether the mesothelioma has spread.
- Endoscopic Biopsies: Long, tube-like cameras are used to view and collect tumor tissue. Endoscopic biopsies can be thoracoscopic, laparoscopic or mediastinoscopic. The biopsy types look at the chest, abdomen and lymphatic system respectively. Endobronchial ultrasound needle biopsies can also be used to look at lymph nodes around the airway.
- Thoracotomy Biopsies: An invasive, open-chest biopsy is used for extracting larger amounts of tissues. Thoracotomy biopsies allow doctors to look closely for possible tumors along the heart or lung linings.
Doctors must take samples from multiple parts of the tumor because different cell types can make up one mesothelioma tumor. Knowing which cell types are present is an important part of a mesothelioma diagnosis. Cell type greatly determines treatment options and prognoses because some cell types are easier to treat than others.
Tumor samples are then analyzed under a microscope by pathologists, or scientists who study diseases. Microscopic analysis and testing techniques called immunohistochemistry are the only ways to confirm the presence of mesothelioma cells and reach a final diagnosis.
Once doctors have made a diagnosis by location, cell type and stage, they use that information to provide the most appropriate treatments. Doctors need to know as much information as possible to ensure they prescribe the most effective treatments for extending life expectancy and improving quality of life.
Immediately following a diagnosis, your doctor will prescribe a treatment plan that may include curative surgery, chemotherapy, radiation or all three.
After you have received your diagnosis, you may also choose to seek a second opinion from a mesothelioma specialist. Mesothelioma is a rare and complex form of cancer that requires specialized knowledge to fully understand the likely course of the disease.
Obtaining a second opinion can sometimes provide you with new information about your diagnosis. This new information can give you more treatments options and a longer life expectancy.