Peritoneal mesothelioma
Peritoneal mesothelioma starts in the peritoneum, the lining of the abdomen that covers most of its organs. It makes up most mesotheliomas that are not pleural.
Last reviewed October 27, 2026 against the sources listed at the end of this page.
In short
- Possible symptoms include belly pain or swelling, fluid in the abdomen (ascites), nausea, loss of appetite, and weight loss.
- There is no formal staging system; doctors measure how far it has spread in other ways.
- For some people, surgery to remove all visible tumor followed by HIPEC (heated chemotherapy in the abdomen) is an option.
- Because few centers do this surgery often, where you are treated matters.
Symptoms
According to the American Cancer Society, possible symptoms of peritoneal mesothelioma include:
- abdominal (belly) pain
- swelling or fluid in the abdomen
- nausea and vomiting
- loss of appetite
- weight loss without trying
Fluid in the abdomen is called ascites. Draining it (paracentesis) can ease discomfort and gives the lab a sample, though a tissue biopsy is often still needed to confirm the diagnosis.
Staging
The American Cancer Society notes that peritoneal mesothelioma has no formal staging system. Doctors still map how much of the abdomen is involved, usually from CT or other scans and during surgery, because that decides whether the tumor can be removed.
Treatment with surgery and HIPEC
NCI describes cytoreductive surgery (removing all the tumor the surgeon can see) followed by hyperthermic intraperitoneal chemotherapy (HIPEC). In HIPEC, a heated chemotherapy solution is pumped into and out of the abdomen to reach cancer cells that remain. NCI's summary for health professionals says this approach is offered to people whose disease is limited to the abdomen, who are well enough for major surgery, and in whom the surgeon expects to remove all visible tumor.
When surgery is not an option, chemotherapy is used. NCI notes that some drug combinations proven in pleural mesothelioma have not been studied as thoroughly in peritoneal disease, so clinical trials may be worth asking about.
Choosing where to be treated
Cytoreductive surgery with HIPEC is a long, specialized operation. It is reasonable to ask a surgeon how many of these procedures the team does each year. NCI-designated cancer centers are a good starting point; see finding a treatment center.
Exposure history
Peritoneal mesothelioma is also linked to asbestos. NCI notes that asbestos fibers can be swallowed as well as breathed in. Family members of asbestos workers may have been exposed through dust on work clothes. If you are not sure how exposure happened, the asbestos exposure page lists common jobs, products, and places.
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Start the free reviewThis page is general health information, summarized from the sources below. It is not medical advice. Talk with your own doctor or care team about your situation.
Sources
- About mesothelioma: types and subtypes (American Cancer Society)
- Signs and symptoms of mesothelioma (American Cancer Society)
- Stages of mesothelioma (American Cancer Society)
- Mesothelioma treatment, patient version (National Cancer Institute PDQ)
- Mesothelioma treatment, health professional version (National Cancer Institute PDQ)