Pseudomyxoma Peritonei (PMP Cancer)

What is Pseudomyxoma peritonei?

Pseudomyxoma peritonei (SOO-doh-mix-OH-muh PAYR-ih-TOH-nee-EYE) is a very rare type of cancer that affects your peritoneal cavity (your abdomen and pelvis). It fills your abdomen and pelvis with cancer cells that produce mucin. Mucin is a jelly-like substance that’s one of the components of mucus.

The condition’s name literally means “false mucinous tumor of the peritoneum.” Healthcare providers call this disease a false tumor because the cancer doesn’t form a tumor that can spread. Instead, the disease starts as a cancerous polyp in your appendix.

When the polyp breaks through your appendix. It triggers a flood of mucin-producing cancer cells that, over time, affect your digestive system. That flood of jelly-like mucin is why some people call PMP “jelly belly.”

Pseudomyxoma peritonei symptoms tend to be mild and may feel like common issues like constipation or indigestion. Sometimes, healthcare providers detect PMP early on while doing your annual exam or while checking for another medical condition. If you’re like most people, however, you’ll find out you have PMP because your belly issues don’t go away or get worse.

What are the symptoms of pseudomyxoma peritonei?

Pseudomyxoma peritonei symptoms develop slowly and you may not notice them or assume your symptoms are from a common illness. Symptoms may include:

• Abdominal distension (swollen abdomen). This is when your abdomen is noticeably swollen.
• Abdominal pain. This may feel like general discomfort or pain as mucin builds up in your belly.
• Constipation. Abdominal swelling may block your large intestine so you can’t pass poop.
• Difficulty getting pregnant. Pressure from mucin buildup or inflammation in your reproductive organs can make it difficult to conceive, especially for people assigned female at birth.
• Hernias. Mucin buildup may push one of your organs through a gap in your muscle wall. Inguinal hernia is one of the most common PMP signs in people assigned male at birth.
• Loss of appetite.
• Nausea.

What causes pseudomyxoma peritonei?

Experts aren’t sure what causes the chain of events that leads to pseudomyxoma peritonei. They do know the disease starts with a polyp in your appendix that sends mucin-producing cancer cells into your perineum. Pseudomyxoma peritonei is very rare. It affects between 1 and 4 people per 1 million each year.

How do healthcare providers diagnose pseudomyxoma peritonei?

A healthcare provider will ask questions about your symptoms, like when you first noticed them or if they’re getting worse. They’ll do a physical examination and order blood tests and imaging tests.

Blood tests

A provider may order a complete blood count (CBC) and blood tests to look for tumor markers. Tumor markers are substances in your body that may indicate signs of cancer.

Imaging tests

Your provider may order the following imaging tests to look for issues like enlarged organs, fluid buildup in your abdomen (ascites) or mucin deposits in your belly (jelly belly):

• Abdominal ultrasound.
• CT scan.
• MRI.

A provider may also do a needle biopsy to get fluid or tissue from your peritoneum. A medical pathologist will examine fluid or tissue cells under a microscope (cytology). A provider may also do a laparoscopy to look at the inside of your belly or to take tissue samples for analysis.

How is pseudomyxoma peritonei treated?

Treatment will depend on your situation, including your health. In some cases, healthcare providers can treat and often cure pseudomyxoma peritonei.

That treatment often involves surgery to remove all organs with cancerous tissue. You may receive intraperitoneal chemotherapy during your surgery. This is chemotherapy that providers place directly into your abdomen.

Your surgeon will do this only if surgery removes all or almost all of the tumor or mucin. They’ll make that decision during your surgery.

Different types of surgery treat pseudomyxoma peritonei.

For example, if you have mucin in your small or large intestine, your provider will remove do a bowel resection. Other surgeries to remove specific organs include:

• Cholecystectomy to remove your gallbladder.
• Hysterectomy with bilateral salpingo-oophorectomy to remove your fallopian tubes, ovaries and uterus.
• Liver capsulectomy to remove part of the surface of your liver.
• Omenectomy, which is removing the layer of fat that covers the front of your belly.
• Peritonectomy to remove your peritoneum. This is the membrane that lines the inside of your abdomen and pelvis.
• Splenectomy to remove your spleen.

What are the complications or side effects of surgery?

There’s always a chance that surgery to remove organs will cause complications like hemorrhage, infection or anastomotic leak (leakage from new bowel connections). Major surgery can cause life-threatening complications. About 1% to 2% of people die after major surgery.

What are nonsurgical treatments for pseudomyxoma peritonei?

Your healthcare provider may recommend one of the following nonsurgical treatments:

• Active surveillance. Your provider may recommend active surveillance if you have early or slow-growing pseudomyxoma peritonei and the risks of surgery outweigh the current risks of the disease. In active surveillance, your provider will make regular checks on your overall health. They may do imaging tests and blood tests to see if PMP is spreading.
• Palliative care. If you can’t have surgery, your provider may recommend treatments like chemotherapy or radiation therapy that will slow down PMP and ease your symptoms.

Healthcare providers are investigating small bowel transplantation as treatment when you have PMP in your small intestine.

What can I expect if I have pseudomyxoma peritonei?

In some cases, surgery to remove all the cancer cells in your peritoneal cavity successfully controls the disease for a long time. Other treatments may help you to live longer with it.

What is the survival rate for someone with pseudomyxoma peritonei?

Your survival rate is an estimate of how long you’ll live after receiving treatment for a specific disease. When you think about survival rates, it’s important to remember that pseudomyxoma peritonei is a rare disease that affects very few people. What researchers know about survival rates comes from what they learn from the experiences of small groups of people. If you have this disease, ask your healthcare provider to explain survival rate research and how it may apply in your situation.

How do I take care of myself?

If you have surgery to remove cancer cells or remove some organs, it’s important to remember that your body needs time and rest to recover. Your healthcare provider will explain how a specific surgery, like surgery to remove your spleen, will affect you.

If you don’t have surgery but have palliative care, you may need to have chemotherapy, radiation therapy or other cancer treatments for the rest of your life.

When should I see my healthcare provider?

If you have PMP, you should contact your provider if:

• You have treatment complications like excessive bleeding after surgery or signs of surgical wound infection
• You have treatment side effects that are stronger than you expected
• You have symptoms that may be signs that pseudomyxoma peritonei is coming back after surgery