MESOTHELIOMA
Mesothelioma is a rare and aggressive cancer that develops in the mesothelium, the thin layer of tissue that lines vital internal organs such as the lungs, heart, and abdomen. The disease is directly linked to asbestos exposure, often occurring in workplace settings or environments where asbestos materials were present.
There are four main types of mesothelioma, categorized based on the affected area:
This cancer has an extended latency period, often taking 20 to 50 years after asbestos exposure to develop, as the fibers embed in the mesothelium and cause long-term inflammation that leads to cancerous changes. This latency means that individuals exposed to asbestos decades ago are only now being diagnosed.
While mesothelioma primarily affects men over 60—particularly military veterans, construction workers, and industrial laborers—anyone exposed to asbestos fibers is at risk, regardless of age, gender, or occupation.
High-risk individuals include those who:
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Worked directly with asbestos-containing materials, such as in mining, manufacturing, or construction
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Lived with someone regularly exposed to asbestos, such as a family member who then brought asbestos fibers home on their clothing
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Inhabited buildings containing asbestos, whether through structural materials or insulation
Diagnosing mesothelioma is complex and often involves imaging tests such as chest X-rays or High-Resolution Computerized Tomography (HRCT). A definitive diagnosis is made by examining fluid or tissue samples, typically through a biopsy.
TYPES & SYMPTOMS OF MESOTHELIOMA
There are four main types of mesothelioma: pleural (lungs), peritoneal (abdomen), pericardial (heart), and testicular. Mesothelioma is also classified by cell type – epithelioid, sarcomatoid, or biphasic – depending on the affected cells. In its early stages, mesothelioma symptoms are often mild and can resemble those of more common health issues, leading individuals to overlook them or attribute them to another condition. Below are the different types of mesothelioma and their associated symptoms.
Pleural Mesothelioma
Pleural Mesothelioma is the most common type of mesothelioma, accounting for roughly 75% of mesothelioma diagnoses. This most common form of mesothelioma accounts for approximately 2,500 – 3,000 cases a year in the United States. It affects the tissue that surrounds the lungs known as the pleura. It is caused by inhaling asbestos fibers into the lungs.
Symptoms include:
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Fatigue
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Fever
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Trouble swallowing
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Chest or lower back pain
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Dry, painful cough
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Shortness of breath
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Unexplained weight loss
Peritoneal Mesothelioma
Peritoneal mesothelioma is the second most common type of mesothelioma. It accounts for less than 20% of mesothelioma diagnoses. This form of mesothelioma is discovered in approximately 250 cases a year. It occurs in the lining of the abdomen (the peritoneum). It is caused by the ingestion of asbestos fibers.
Symptoms Include:
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Abdominal pain and swelling
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Loss of appetite
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Lumps of tissue in the abdomen
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Unexplained weight loss
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Nausea and Vomiting
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Constipation
Pericardial Mesothelioma
Pericardial mesothelioma is a rare form of mesothelioma that develops in the lining surrounding the heart (the pericardium). This type of mesothelioma accounts for approximately 5% of the newly diagnosed cases per year.
Symptoms Include:
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Difficulty breathing
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Chest pain
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Heart failure
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Pericardial effusion
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Pulmonary embolism
Testicular Mesothelioma
Testicular mesothelioma is extremely rare, and accounts for less than 1% of mesothelioma diagnoses. This asbestos cancer occurs around the lining of the testicles.
Symptoms Include:
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Pain and swelling of the testicles
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A buildup of fluid or a mass in the scrotum
Cell Types
Mesothelioma can also be classified based on the appearance and behavior of the cancerous cells, regardless of where in the body the disease occurs.
The 3 mesothelioma cell types are:
Epithelioid Mesothelioma
Epithelial cells are one of the four basic types of cells in the human body and line the cavities, blood vessels, and organs throughout the body. Once exposed to asbestos these normally healthy cells mutate into cancer cells or epithelioid mesothelioma. The prognosis for epithelioid mesothelioma is more favorable, with more treatment options available, than those with sarcomatoid or biphasic mesothelioma.
Sarcomatoid Mesothelioma
Sarcomatoid cells are located in connective tissue such as bone, cartilage, muscle, blood vessels, or lymphoid tissue throughout the body. Sarcomatoid mesothelioma is the least common of the mesothelioma cell types and is unfortunately the most resilient to cancer treatment. Diagnosis is difficult because these cells can appear healthy even though they may have become malignant after being damaged from exposure to asbestos. The treatment options available for sarcomatoid mesothelioma are limited and the most common approach is palliative care. This extremely aggressive form of cancer is also known as spindle-shaped/spindle-cell mesothelioma, based on their appearance, or sarcomatous mesothelioma.
Biphasic Mesothelioma
Biphasic mesothelioma is a combination of epithelioid and sarcomatoid cells. Understanding the different types of mesothelioma and which cells have been affected can assist in making important treatment decisions.
The 4 Stages of Mesothelioma Cancer
Stage 1
The earliest stage of mesothelioma and, if discovered during this stage, the patient has the best prognosis and more treatment options available.
Stage 2
During this stage the mesothelioma has not spread to other parts of the body. The cancer is localized and, therefore, patients have more options for treatment. Patients may elect to have surgery, chemotherapy, and/or radiation.
Stage 3
In stage 3, Mesothelioma has already metastasized to other parts of the body making it more difficult to treat. Surgery is generally not an option at this stage since the cancer has already spread.
Stage 4
In the last stage, the mesothelioma has spread throughout the body and affected multiple organs and parts of the body. Patient’s treatment options are extremely limited and typically palliative care is the only course to ease suffering.
DIAGNOSIS OF MESOTHELIOMA
Mesothelioma is often diagnosed after a person visits their doctor due to symptoms they are experiencing. The symptoms of mesothelioma can vary depending on the type, and they often don't appear until the disease is at an advanced stage. If you have a history of asbestos exposure and are experiencing symptoms such as shortness of breath, chest pain, or abdominal discomfort, it is important to contact your doctor. Early diagnosis is crucial to improving your treatment options and overall prognosis.
During an initial evaluation, your physician will take a detailed medical and work history, including any known asbestos exposure, and conduct a physical exam. Since mesothelioma is rare and shares symptoms with many other conditions, it is essential to inform your doctor about your asbestos exposure history. Without this information, the possibility of mesothelioma might not be considered early on.
If your doctor suspects mesothelioma, they may refer you to a specialist, such as a pulmonologist or oncologist, for further evaluation. This evaluation typically involves imaging tests, such as X-rays or CT scans, and possibly blood tests. If these initial tests suggest mesothelioma, a biopsy will be ordered to confirm the diagnosis and determine the best course of treatment.
Imaging Tests
Imaging tests such as x-rays, CT scans, PET scans and MRIs, are used to take pictures of the inside of your body. These tests can be used to look for cancer, find out how far the cancer has spread, and determine whether cancer treatment is working. If an abnormal mass that resembles mesothelioma is detected, your doctor will order a biopsy.
Blood Tests
Blood tests for mesothelioma include the MESOMARK test, SOMAmer test and Human MPF test. These blood tests cannot confirm a diagnosis of mesothelioma, however, there are 3 substances in the blood which may be elevated (fibulib-3, osteopontin, and soluble mesothelin-related peptides (SMRPs) in individuals who have mesothelioma, therefore, high levels of these substances can make a mesothelioma diagnosis more likely.
Biopsy
Only a biopsy can determine a mesothelioma diagnosis. It is the last stage of the diagnostic process. It involves removing cells from an abnormal area in the body and examining the cells under a microscope. There are three types of biopsies that are used for mesothelioma: fine-needle biopsies, endoscopic biopsies, and open surgical biopsy.
Fine Needle Aspiration
A long, thin, hollow needle is inserted directly into the mass to obtain tissue samples. This is a quick procedure and there is little downtime, however, in some cases, the tissue sample may be too small to make a diagnosis and a more invasive procedure may be needed, such as a surgical biopsy.
Endoscopic Biopsy
An endoscopic biopsy involves the use of a narrow, flexible tube called an endoscope, equipped with a tiny camera and a light. This tool is inserted through a small incision in the body to obtain tissue samples. The procedure is typically performed in an operating room under general anesthesia, ensuring precision and patient comfort. There are 3 different types depending on the type of mesothelioma:
Laparoscopy for peritoneal mesothelioma
Laparoscopy is a minimally invasive procedure in which small incisions are made in the abdomen. This allows doctors to examine abdominal organs and collect tissue samples from suspected peritoneal mesothelioma tumors.
Mediatinoscopy for pericardial mesothelioma
Thoracoscopy for pleural mesothelioma
A thoracoscopy involves making a small incision in the chest wall to directly view the pleura. This procedure is used to obtain tissue samples from suspected pleural mesothelioma tumors and helps confirm a diagnosis.
During a mediastinoscopy, a small incision is made at the base of the neck to access the area between the breastbone and the lungs (the mediastinum). This procedure allows doctors to examine this region and collect tissue samples from suspected pericardial mesothelioma tumors.
Open Surgical Biopsy
Sometimes, when a needle or endoscopy biopsy is not able to confirm a diagnosis or the location of the tumor is too hard to reach using a needle or endoscope, a more invasive open surgical biopsy may be needed to obtain a tissue sample. In this case, an open surgical biopsy will take a larger sample of the tumor or, in some cases, remove the entire tumor entirely. There are 2 types of open surgical biopsies depending on the type of mesothelioma:
Thoracotomy
A thoracotomy is performed on patients who may have either pleural mesothelioma or pericardial mesothelioma. It is an open-chest surgical procedure.
A laparotomy is performed on patients who may have peritoneal mesothelioma. It is an open abdominal procedure.