Peritoneal Cancer | Mesothelioma | MedStar Health

Peritoneal surface malignancies are cancers that grow or spread along the peritoneal surfaces, the tissues inside the abdomen that line and protect your lungs, chest, and abdomen. Generally, the cancer originates inside the appendix, colon, or pancreas and spreads into the rest of the abdomen.

The mesothelium is a very thin coating of tissue that lines several body cavities. It includes two layers:

  • One layer that covers the individual organ
  • One layer that forms a pouch to surround all of the organs in the cavity

Fluid fills the space between the layers to offer extra cushioning as the organs gets bumped around in your body. The mesothelium in the abdominal cavity is called the peritoneum.

Peritoneal mesothelioma develops when abnormal cells grow rapidly in the peritoneum. These cancerous cells can disrupt the peritoneum and spread to other organs and tissues in the abdominal cavity. This cancer can also spread to other parts of the body.

Risk factors

There are some risk factors for developing any form of mesothelioma. These include:

  • Exposure to and breathing in of asbestos. The longer and more extensive your exposure to asbestos, the higher your risk of developing mesothelioma
  • While smoking alone is not a risk factor, if you smoke and also were exposed to asbestos, you have an even higher risk of developing the disease
  • Men are more likely than women to develop the disease


Diagnosing peritoneal mesothelioma can be challenging since symptoms often do not appear until 20 to 30 years after exposure to asbestos and because they are also common to other illnesses. Talk to and inform your doctor of any exposure to asbestos if you experience any suspicious symptoms or the following:

  • Abdominal pain
  • Abdominal swelling
  • Weight loss
  • Blockages in your bowels
  • Problems with blood clotting
  • Anemia
  • Fever


Other important tools your doctor may use to diagnose peritoneal mesothelioma include:

  • Peritoneoscopy: In this procedure, your doctor uses a special instrument called a peritoneoscope to remove suspicious tissue from your abdominal area
  • Surgery: If your doctor cannot get a conclusive diagnosis from your biopsy and/or peritoneoscopy, you may need surgery. This will give your doctor a better look and allow for a more complete understanding of your condition

If you have peritoneal mesothelioma, your doctor will then determine the stage of cancer, which may involve further tests to determine how far the tumors have spread in the abdominal cavity, as well as determine the most effective treatment program.

The mesothelium is a very thin coating of tissue that lines several body cavities. Fluid fills the space between the layers to offer extra cushioning as the organs gets bumped around in your body. The mesothelium in the abdominal cavity is called the peritoneum.

Peritoneal carcinomatosis is a rare type of cancer that affects the peritoneum. It develops when existing abdominal cancers, including appendix, colon, rectal, and pancreatic cancers, spread into the peritoneum. This causes tumors to grow throughout the peritoneum. The spread of an abdominal cancer to the peritoneum usually means that your abdominal cancer is in an advanced stage.

Another form of the disease, primary peritoneal carcinomatosis, begins in the peritoneum itself. This is also a rare condition, and tends to affect women who are also at risk for ovarian cancer.


Peritoneal carcinomatosis caused by abdominal cancers can create a condition called ascites. Ascites is an abnormal pooling of fluid in the peritoneum, which can cause the following additional symptoms:

  • Uncomfortable swelling of the abdomen
  • Swelling of the ankles
  • Pain in the stomach area
  • Breathing problems
  • Unusual weight gain
  • Loss of appetite
  • Digestive problems, like nausea and constipation
  • Extreme tiredness

Primary peritoneal carcinomatosis, especially in its early stages, may not produce many unusual symptoms. Often, people do not notice symptoms until the cancer is advanced. Noticeable symptoms may be similar to those listed above.

Diagnosis and treatment

If there is any suspicion that you may be developing either form of peritoneal carcinomatosis, your doctor will review your medical history and perform a variety of tests to confirm a diagnosis.

Treatment for peritoneal carcinomatosis is generally fairly aggressive, since it is an advanced form of cancer. To prevent the cancer from spreading even further, treatment typically includes surgery followed by chemotherapy.

  • Cytoreductive, or debulking surgery, is an extensive procedure that removes as much of the tumor from the area as possible. It may require removing parts of other affected organs, like the bowels, liver, gall bladder, spleen, pancreas, and stomach. For women, this may also require removing the uterus and ovaries
  • Immediately following the removal of the tumor or parts of the peritoneum, your doctor will administer hyperthermic intraperitoneal chemotherapy (HIPEC), in which the inside of the abdomen is bathed with a heated chemotherapy solution to kill any possible remaining cancer cells left over from surgery. The combination of heat and cancer-killing medication has been proven to be the most effective treatment for peritoneal malignancies, and it allows you to receive higher doses of medication without significantly affecting the rest of your body
  • In a hemicolectomy, your specialist removes part of the colon and possibly affected blood vessels and lymph nodes
  • In a peritonectomy, the peritoneum is stripped away to remove tumors from the lining of the peritoneal cavity

Appendix cancer is rare, occurring in about 1,000 people in the United States each year. In those cases, abnormal cells grow wildly in your appendix (a small pouch connected to your colon with no known purpose) and form a tumor. Tumors can be either benign (non-cancerous) or malignant (cancerous).


The primary types of appendix tumors include:

  • Carcinoid, adenocarcinoid, and goblet cell appendix tumors are slow-growing tumors that begin in the appendix and account for about half to two thirds of all appendix cancers. These tumors often do not cause symptoms unless they spread to other organs
  • Colonic-type adenocarcinomas are tumors that occur in about 10 percent of appendix cancer cases, developing at the bottom of the appendix, near the colon
  • Signet-ring cell adenocarcinoma is the rarest and most aggressive form of appendix cancer
  • Non-carcinoid appendix tumors are tumors that begin in the wall of the appendix and produce a thick, sticky substance called mucin

    • The mucin in non-carcinoid appendix tumors can spread into the abdominal space that holds the intestines, stomach, and liver and cause tumors to spread to this area
    • About 20 percent of non-carcinoid appendix tumors produce enough mucin to fill the peritoneal cavity. These tumors, known as mucinous cystadenocarcinomas, can block the bowels, prevent them from working properly, and cause abdominal pain, bloating, and shortness of breath
    • A condition called pseudomyxoma peritonei can develop when an appendix tumor breaks through the appendix and causes very thick mucin to flow throughout the peritoneal cavity. The mucin spreads throughout the abdominal space in a certain pattern. It surrounds the digestive organs, like the colon, small bowel, and liver, and eventually stops them from functioning properly


Appendix cancers may not cause any symptoms, or they may cause vague symptoms that you can easily ignore until they cause a real problem. This is why it is important to alert your doctor to any new or unusual symptoms, including:

  • Discomfort in the lower right section of your abdominal area
  • Bloating
  • An inflated abdomen, caused by fluid build up
  • Reflux
  • Lack of appetite
  • Shortness of breath
  • Problems digesting your food
  • Constipation and/or diarrhea

Symptoms of pseudomyxoma peritonei include:

  • Jelly belly, which is a distended abdomen caused by a build-up of mucin
  • In men, an inguinal hernia, in which mucinous tumor and/or a part of the small intestine bulges through a weak area in the lower abdominal area
  • In women, an ovarian mass or tumor

Symptoms of appendicitis include:

  • Pain and/or swelling in the lower right section of your abdominal area
  • Fever
  • Vomiting and/or nausea
  • Lack of appetite
  • Constipation and/or diarrhea

Diagnosis and treatment

Appendix tumors often go undetected because symptoms are easily explained away. Your doctor may find them during a routine examination or an abdominal procedure for a different problem, which can include appendicitis, infertility, hernia, ovarian tumors, or infertility.

Treatment for both appendix cancer and pseudomyxoma peritonei depends on your individual circumstances, as well as the stage of the disease. In many cases, treatment involves cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (HIPEC). The treatments may also start with a three-month course of systemic chemotherapy, to be followed by cytoreductive surgery combined with HIPEC.

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