What Is Peritoneal Mesothelioma?
Peritoneal mesothelioma is an asbestos-caused cancer that develops in the peritoneum. The peritoneum is a thin membrane that covers the abdominal cavity and the organs inside it, such as the stomach, liver, spleen, and intestines.

More rare than its counterpart that develops in the lungs, peritoneal mesothelioma affects about 600 Americans each year.
Despite being the second most common type of mesothelioma, peritoneal mesothelioma has the most favorable prognosis. Patients who undergo cytoreductive surgery with HIPEC live for 5 years or more, in many cases.
How Peritoneal Mesothelioma Develops
- Exposure: Asbestos fibers are swallowed or inhaled and become trapped in the stomach lining.
- Buildup: Over time, the fibers irritate healthy cells and damage cell DNA, causing cancer cells to grow and the peritoneum to thicken.
- Damage: Mesothelioma cells continue growing and spreading, eventually forming tumors.
- Cancer: The invasive peritoneal tumors progress rapidly until treatments help to slow their growth.
Who Is at Risk for Peritoneal Mesothelioma?
People at high risk of asbestos exposure are generally more likely to develop peritoneal mesothelioma. High-risk groups include blue-collar workers, veterans, and those who live near asbestos mines or natural deposits.
Loved ones of individuals exposed to asbestos may also be at higher risk through secondhand exposure.
“I got peritoneal mesothelioma from working with my dad. He was a subcontractor, and he used to take us with him on his job sites.”
– Brenda W., Peritoneal Mesothelioma Victim
Peritoneal Mesothelioma Symptoms
Common symptoms of peritoneal mesothelioma include:
- Abdominal fluid buildup (ascites)
- Abdominal pain
- Bloating (abdominal distention)
- Fever and night sweats
- Fatigue
- Nausea and vomiting
- Loss of appetite
- Unexplained weight loss
The symptoms of malignant peritoneal mesothelioma may not appear until 20-50 years after the initial exposure to asbestos. These symptoms tend to be mild and vague, so many patients aren’t diagnosed until after their cancer has spread.
Peritoneal Mesothelioma Diagnosis
In order to confirm a peritoneal mesothelioma cancer diagnosis, your doctor must perform a biopsy. They may also use imaging tests to look for signs of cancer and rule out other diseases.
Imaging Tests
Imaging tests are the first step in the diagnostic process for peritoneal mesothelioma. Patients who report abdominal pain and swelling may receive X-rays, a computed tomography scan (CT scan), or magnetic resonance imaging (MRI).
Biopsies
Next, if your doctor suspects cancer, they will perform a biopsy. During this procedure, your doctor will collect a fluid or tissue sample and examine it under a microscope to see if cancer cells are present.
Types of biopsies for peritoneal mesothelioma include fine-needle aspiration, core needle biopsy, or diagnostic laparoscopy. Although biopsies are more invasive than imaging tests, doctors rely on them to make a confident diagnosis.
Diagnosing Peritoneal Mesothelioma Stage
Peritoneal mesothelioma is not staged using the typical Tumor Node Metastasis (TNM) cancer staging system because it advances in an unusual way, often remaining in the abdomen instead of spreading to other parts of the body.
Peritoneal mesothelioma is instead classified as early or advanced.
Getting a Second Opinion
Because peritoneal mesothelioma is a rare cancer, even an experienced oncologist can misdiagnose it — which could delay or eliminate the possibility of curative treatment.
If you have any questions about your diagnosis, it’s critical to get a second opinion from a specialized mesothelioma doctor.
We can help you find a specialist near you — contact us today.