What Is Pseudomyxoma Peritonei?

Medically Reviewed by Minesh Khatri, MD on May 28, 2023
3 min read

Pseudomyxoma peritonei (PMP) is a rare condition that usually starts with a tumor in your appendix -- though the tumor also can be in your bowel, bladder, or ovaries. Only about 1 in a million people get it.

PMP may not cause any problems until the tumor grows and bursts out of the area where it started. When it enters your abdomen (belly), more tumors form and make mucinous fluid, a jelly-like material. This eventually fills up your belly, which is why PMP is sometimes known as "jelly belly."

When this fluid builds up in your abdomen, it can push on other body parts. That causes swelling and digestion problems. It can even block your intestines or cause them to fail. This can be very serious and even life threatening.

Doctors don't really know what causes PMP. It doesn't run in families. And it doesn't seem to be linked to anything in the environment.

Some doctors break PMP into two groups:

  • Disseminated peritoneal adenomucinosis (DPAM) is the benign type, which means it's not cancerous. But if it's not treated, it can still be serious or even deadly.
  • Peritoneal mucinous carcinomatosis (PMCA) is the type in which cells from the tumor do show cancer.

You may not have any symptoms at first. But some of the following may appear over time:

  • Belly pain
  • Changes in your bowel habits
  • Enlarged ovary in women
  • Hernia (a bulge near your groin)
  • Poor appetite
  • Swollen belly
  • Weight gain or a bigger waist size

It can be hard to diagnose PMP because it may look and act like other diseases. Sometimes it's found by accident when you're being treated for something else.

To find out if you have it, your doctor will examine you and ask questions about your symptoms. Then they'll want to get pictures of the inside of your belly and other areas of your body.

One way to do this is by a CT scan. It takes a number of X-rays from different angles and puts them together to give more information. Sometimes you may take a special drink or get dye that makes the image easier to see.

A magnetic resonance imaging scan, or MRI, is another painless way to get a picture. It uses powerful magnets and radio waves to make detailed images.

Other ways to diagnose PMP include:

  • Ultrasound scan: This uses sound waves to make a picture.
  • Laparoscopy: A fiber-optic instrument is put through a small cut in your abdomen wall so your doctor can see inside.
  • Biopsy: A small amount of tissue is taken to be looked at under a microscope.

The best way to treat PMP depends on the type of tumor -- cancerous or noncancerous -- the size of the tumor, and how healthy you are. Your doctor may recommend:

  • Wait and watch: If the tumor is small and not growing very fast, the doctor may just ask you to come in regularly to check on it.
  • Debulking surgery: This takes out as much of the tumor as possible. It won't cure PMP, but it can help you feel better.
  • Cytoreductive surgery: Your surgeon will take out the lining of your abdomen and any tissues that are affected. Then they'll put chemotherapy drugs into your abdomen. Afterward, more chemotherapy and another cancer-fighting drug called fluorouracil may be put in the area to kill off any cells from the tumor that were left behind. This is a major operation, and it can take a long time to recover. But it can cure PMP.
  • Chemotherapy: If you can't have cytoreductive surgery, the doctor may suggest you have chemotherapy. The drugs may be given through your veins.