How Is Mesothelioma Diagnosed?

Medically Reviewed by Dr. F. Perry Wilson

The earlier mesothelioma is accurately diagnosed, the more effective treatments can be.

Mesothelioma has a long latency period and it can take decades for symptoms to develop after someone is first exposed to asbestos.

If there is a reason to suspect you may have mesothelioma, a qualified medical professional will review your medical history, perform a physical examination and use a variety of diagnostic tests for diagnosing mesothelioma to confirm the presence of the disease.

How Mesothelioma is Diagnosed

When understanding how to diagnose mesothelioma, you should first know the symptoms and warning signs of asbestos exposure. These symptoms usually do not appear immediately but rather develop over time — even up to 40 years after following exposure. Respiratory issues such as a dry cough, shortness of breath, chest tightness or pain, weight loss and clubbed fingers are all possible symptoms of developing mesothelioma.

If you suspect you have been exposed to asbestos or are experiencing any symptoms, it is crucial to seek medical attention and consult a doctor to properly diagnose mesothelioma.

Medical History and Physical Examination

A complete medical history (interview) is taken to check for mesothelioma risk factors and symptoms. This interview includes questions to determine where asbestos exposure may have occurred as well as the duration and amount of asbestos exposure the patient was subjected to.

A physical exam will provide information about signs of mesothelioma and other health problems. For example, a physical exam may detect:

  • Pleural effusion, or fluid in the chest cavity, indicating pleural mesothelioma
  • Ascites, or fluid in the abdominal cavity, indicating peritoneal mesothelioma
  • Pericardial effusion, or fluid in the pericardium, indicating pericardial mesothelioma

If other symptoms are present such as shortness of breath, pain and weakness, they will also be evaluated to help diagnose mesothelioma.

Imaging Scans

PET scans, X-rays, CT scans and MRIs are useful diagnostic imaging tools for diagnosing mesothelioma and evaluating the stage the cancer has progressed to. Each test provides doctors with a different view or type of information to help them make their diagnosis.

  • PET Scan: This is a nuclear medicine imaging technique doctors use to stage mesothelioma, as it can detect how far the disease has advanced. A PET scan will produce an image of the metastasizing or malignant mesothelioma cancer if other surrounding tissue is affected.
  • MRI: This scan is used by mesothelioma doctors to diagnose mesothelioma and assist with staging the disease. An MRI uses magnetic fields rather than X-rays to create images of areas of the body suspected to show cancer.
  • CT Scan: This scan enables doctors to have a detailed cross-sectional image of the area of the body suspected of showing cancer. At times, a harmless dye may be injected into the veins to highlight certain details on the CT scan.
  • X-Ray: Patients that have mesothelioma often show signs of irregular thickening of the pleura, fluid in the pleural space, pleural calcifications (mineral deposits) and spaces between the lobes of the lungs. These characteristics of mesothelioma can be identified through X-rays.


Biopsies are frequently used for conclusively diagnosing mesothelioma. The two primary types of biopsy procedures are needle biopsies and surgical biopsies. A biopsy is an important diagnostic procedure doctors recommend for patients with a history of prior asbestos exposure who are presenting with signs and symptoms of mesothelioma.

Common biopsies for diagnosing mesothelioma include:

  • Needle Biopsy: A fine needle biopsy is a less invasive procedure. It’s sometimes referred to as a closed biopsy. More invasive surgical biopsies are recommended if results from a needle biopsy are inconclusive or if a needle biopsy is not recommended for medical reasons.
  • Pleural Biopsy: Pleural effusion is a common symptom in mesothelioma patients. If a patient presents with this symptom, their doctor will likely recommend a pleural biopsy, the most common closed biopsy procedure. This test, which can be performed in a radiologist's office, is considered a minimally invasive procedure to obtain a fluid and tissue sample from the chest area and the pleural membrane. Once obtained, it is sent to the lab for examination. The procedure itself has few risks associated with it and can be performed on an outpatient basis.
  • Thoracentesis: Patients presenting with excessive fluid buildup in the chest area may be required to undergo a thoracentesis. This procedure, also considered a “closed needle” procedure, is designed to obtain a fluid sample from the pleural space (to see if pleural mesothelioma is present) as well as remove excess fluid so the patient will be more comfortable.
  • Paracentesis: Peritoneal patients often experience the symptom of excess fluid buildup in the abdominal area. If excess abdominal fluid exists, a paracentesis may be recommended. It is essentially the same procedure as the thoracentesis described above except the purpose is to drain excess fluid from the abdominal region rather than the chest. It can make the patient more comfortable and allow doctors to obtain a fluid sample to help diagnose mesothelioma.
  • Surgical Biopsy: When less invasive needle biopsies produce inconclusive results or it is determined unsafe to perform them, a surgical biopsy may be recommended. It is a more invasive procedure and generally requires hospitalization.
  • Thoracoscopy: A thoracoscopy is a diagnostic procedure doctors use to help detect the presence of pleural mesothelioma. This procedure uses a thoracoscope (telescope-like instrument connected to a video camera) that is inserted into the chest through a small incision. Through the thoracoscope, a doctor can view the tumor and take a tissue biopsy using special forceps.
  • Thoracotomy: If a tumor has been detected in the chest area and the doctor suspects that the patient may have pleural mesothelioma, a thoracotomy may be ordered. A thoracotomy is considered open surgery. In this procedure, a surgeon makes an incision in the chest wall. This allows them to perform an examination around the lungs and to obtain a tissue sample from a tumor. In some instances, the tumor will be removed in its entirety.
  • Laparoscopy: Similar to thoracoscopy, a laparoscopy allows surgeons to examine organs in the abdominal region and perform a biopsy of abnormal tissue using video-assisted technology.
  • Laparotomy: A laparotomy is also an open surgery and is similar to a thoracotomy. This surgery, however, is performed in patients suspected of having peritoneal mesothelioma. It allows the surgeon to open the abdominal cavity, examine the tumor and surrounding tissue, obtain a biopsy sample and, if necessary, remove the tumor altogether.
  • Mediastinoscopy: This procedure allows doctors to examine the lymph nodes in a suspected area and remove samples to test for cancer. Lung cancer is known to spread to lymph nodes but is not characteristic with mesothelioma. A mediastinoscopy can help doctors distinguish lung cancer from mesothelioma and help determine if the cancer is localized or has begun to spread to other areas of the body.

What to Do After a Mesothelioma Diagnosis

If diagnosed with mesothelioma, of course, your health and treatment should be the number-one priority. However, keep in mind you may also be eligible for financial compensation to assist with medical bills and other costs.

Consult with a Specialist

Seek out a medical oncologist or mesothelioma specialist with experience in treating this rare form of cancer. They can provide you with the most up-to-date information about your specific case and treatment options.

Given the complexity of mesothelioma, it can be beneficial to get a second opinion from another qualified specialist to confirm the diagnosis and stage of the disease and explore additional treatment options.

Develop a Treatment Plan

Work with your medical team to develop a personalized treatment plan based on the stage of your cancer, your overall health and your preferences. Treatment options may include surgery, chemotherapy, radiation therapy, immunotherapy or a combination of these.

Address Financial Matters and Take Legal Action

Mesothelioma treatment can be expensive, so it’s essential to explore your health insurance coverage and available financial assistance options.

Additionally, if you believe you were exposed to asbestos due to someone else’s negligence (e.g., in the workplace), consider consulting a lawyer to understand your legal rights and potential compensation.

Statute of Limitations Following Mesothelioma Diagnosis

The statute of limitations — or legal time limit within which a person must file a lawsuit — after diagnosing mesothelioma varies depending on the jurisdiction and specific circumstances. If you miss the deadline, you may lose your right to seek compensation through the legal system. Thus, it's crucial to consult with an attorney who specializes in mesothelioma and asbestos-related cases, as they can provide accurate information about the statute of limitations that applies to your case.

Keep in mind that if you believe your mesothelioma was caused by asbestos exposure in the workplace, there may be additional considerations regarding workers' compensation and other legal avenues. An experienced attorney can guide you through the process and help you understand your rights and options.

At ELSM, our lawyers specialize solely in mesothelioma cases and have worked closely with victims of this cancer for decades. To begin receiving the help and compensation you deserve, contact us today for a free evaluation.

Mesothelioma Symptoms

It can be extremely difficult to pinpoint mesothelioma because its symptoms are seemingly non-threatening and so similar to other illnesses. The symptoms most commonly associated with mesothelioma often mimic those of other less threatening upper respiratory illnesses. For instance, mesothelioma is often confused with pneumonia in its early stages.

Most people experience symptoms for about two to six months before seeking medical attention. Some people do not even experience any symptoms, and the tumors are found accidentally through a routine X-ray or exam.

Symptoms of Pleural Mesothelioma

Patients with pleural mesothelioma often suffer from pain in the side of the chest or the lower back. Other symptoms include:

  • Shortness of breath
  • Difficulty swallowing
  • Chest pains
  • Weakness
  • Coughing blood
  • Sensory loss

Symptoms of Peritoneal Mesothelioma

Peritoneal mesothelioma can cause pain in the abdomen, due to the swallowing of asbestos fibers. Symptoms include:

  • Weight loss
  • Nausea
  • Vomiting
  • Hernia
  • Swelling of the abdomen

If you are experiencing any of these symptoms and have come in contact with asbestos in the past, you should consult your doctor immediately. It is important to tell your doctor all of your symptoms, no matter how trivial, because they can be the key to your diagnosis. It is also imperative to tell your doctor about any exposure to asbestos.

Frequently Asked Questions

How is mesothelioma diagnosed?

Diagnosing mesothelioma involves a combination of medical history review, physical examination, imaging tests and biopsy. The diagnostic process aims to identify the presence of mesothelioma, determine its type and assess its stage (extent of spread).

What do I do after a mesothelioma diagnosis?

If you are diagnosed with mesothelioma, your first step should be to seek the highest-quality medical care and treatment options. It may also be beneficial to get a second opinion or referrals to specialists who can help ensure the best outcome. In addition, consider seeking legal counsel if you believe your diagnosis is the result of another party’s wrongdoing, as you could receive monetary compensation.

How do you diagnose mesothelioma early?

Diagnosing mesothelioma early can be challenging because the disease often presents with vague symptoms that can mimic other more common conditions. Some steps that can help in diagnosing mesothelioma at an earlier stage include:

  • Knowing the risk factors (namely asbestos exposure).
  • Getting regular health checkups to identify concerning symptoms.
  • Familiarizing yourself with common early symptoms (like persistent cough, chest or abdominal pain, shortness of breath, fatigue, unexplained weight loss and difficulty swallowing).
  • Ordering imaging tests to detect abnormalities (like chest X-rays, CT scans or MRI scans).
  • Getting a biopsy to confirm diagnosis.
  • Seeking specialist consultation to accurately interpret test results.

Request a Free Case Evaluation

Request a free case evaluation now if you or someone you love has been diagnosed with mesothelioma. The evaluation will cost you nothing. Our lawyers will travel to visit you at your convenience or conference call with you over the phone. We understand how difficult a time this is for you and will assist in any way that we can. You can also call us toll-free at 1-800-336-0086 at any time.

Dr. F. Perry Wilson Medically Reviewed by Dr. F. Perry Wilson

Dr. F. Perry Wilson is a board-certified physician. He serves as Associate Professor of Medicine at the Yale University School of Medicine and is the Interim Director at the Yale Program of Applied Translational Research. Dr. Wilson is a contributor on the editorial team and is responsible for ensuring that all medical content is accurate.