Peritoneal mesothelioma is cancer of the peritoneum, the thin lining that covers the organs and inner walls of the abdomen. It is the second most common form of mesothelioma. The American Cancer Society reports that pleural cases make up about three in four mesotheliomas, and peritoneal cases account for most of the rest. Like the pleural form, it is caused by asbestos exposure, according to the National Cancer Institute.
This page is informational, not medical advice. Testing and treatment decisions belong with your care team.
Peritoneal Mesothelioma Symptoms: Abdominal Pain, Swelling, and Fluid Buildup
According to the American Cancer Society, common signs include:
- abdominal pain
- swelling of the belly
- fluid buildup in the abdomen (called ascites)
- nausea and vomiting
- constipation
- unexplained weight loss
None of these symptoms points to a rare cancer on its own. They can look like gallbladder disease, a hernia, ovarian problems, or ordinary digestive trouble. Peritoneal mesothelioma is often investigated under those labels for some time before the correct diagnosis is made.
If these symptoms persist in someone with any history of asbestos exposure, that history should be part of the conversation with the doctor.
How Asbestos Exposure Causes Peritoneal Mesothelioma
Asbestos fibers enter the body when they are inhaled or swallowed. The NCI fact sheet states that trapped fibers can cause disease in the linings of the abdomen and chest.
The exposure sources are the same ones behind every asbestos disease. These include industrial and trade work. They also include household exposure from fibers carried home on work clothes, which the NCI also documents.
Asbestos diseases can take decades to develop, so the exposure behind a diagnosis today usually traces back to jobs held many years ago. Our asbestos exposure guide covers where those exposures happened in Pennsylvania.
How Peritoneal Mesothelioma Is Diagnosed: Imaging, Paracentesis, and Biopsy
The diagnostic path is similar to the pleural workup: imaging comes first, then fluid testing, then a tissue sample.
According to the ACS, doctors may drain abdominal fluid with a needle (a procedure called paracentesis) and test it. However, only a biopsy confirms the disease. The biopsy is often taken during a camera-guided procedure called laparoscopy.
Unlike pleural mesothelioma, the peritoneal form has no established formal staging system. The ACS staging guide notes that the formal system applies to pleural disease. For peritoneal disease, doctors instead describe how far it has spread using imaging and surgical findings.
Peritoneal Mesothelioma Treatment Options: Surgery, HIPEC, and Chemotherapy
The ACS surgery guide describes the approach used for some peritoneal patients. Surgeons remove as much of the tumor as possible from the abdomen. This is often combined with heated chemotherapy circulated through the abdominal cavity during the operation.
Chemotherapy given through a vein is also used. The National Cancer Institute’s treatment summary (NCI PDQ) covers the full range of treatment categories for mesothelioma.
Whether surgery is a good fit depends on how far the disease has spread and on the person’s overall health. That judgment belongs to the treating team. Our treatment overview explains each treatment category in plain terms.
Peritoneal Mesothelioma Prognosis and Survival Rates
Mesothelioma survival statistics are usually reported for the pleural form, where patient numbers are largest and research is most extensive. The American Cancer Society reports a five-year relative survival rate of about 12 percent for pleural mesothelioma across all stages.
Those figures have important limits:
- They are group averages based on patients diagnosed years ago.
- The ACS is clear that they cannot predict what will happen to any one person.
- They do not apply neatly to the peritoneal form, which is treated differently and behaves differently.
For a peritoneal patient, the outlook depends on several factors: the extent of disease, whether surgery is possible, the cell type, and overall health. The treating oncologist is the only person who has all of those facts. Our prognosis page explains what survival statistics can and cannot tell one family.
Peritoneal vs. Pleural Mesothelioma: Key Differences
The two forms differ in location, symptoms, and treatment planning, but they share the same cause. Both are mesothelioma, both are confirmed by biopsy, and both can support a compensation claim.
The pleural form is covered on our pleural mesothelioma page, and the full group of asbestos diseases is mapped on the asbestos diseases hub.
One practical note for families: because the peritoneal form is less common, getting a second opinion from a major cancer center is common and worth asking about.
Peritoneal Mesothelioma Compensation and Legal Rights in Pennsylvania
Legally, a peritoneal mesothelioma diagnosis stands on the same footing as a pleural one. Families may be able to file claims against the companies responsible for the exposure. They may also qualify for compensation from asbestos bankruptcy trust funds. According to the U.S. Government Accountability Office (GAO-11-819), these trusts were funded with billions of dollars set aside for asbestos victims.
Pennsylvania sets strict deadlines for filing these claims, and the timing usually depends on when the disease was diagnosed or discovered. That is why it matters to get legal guidance soon after a diagnosis.
Many peritoneal patients undergo a lengthy diagnostic process before receiving the right diagnosis. That process does not weaken a claim. An attorney can review how the deadline applies to your family’s specific situation.
If peritoneal mesothelioma has been diagnosed in your family, request a free case review to get clear answers about your deadline and the path forward.