Symptoms of Pseudomyxoma Peritonei (PMP)

Pseudomyxoma peritonei (PMP) is a rare, slow-growing cancer that commonly starts in the appendix. PMP symptoms typically take a long time to develop, and some patients do not show any of the symptoms for a number of years. As a result, this condition can be difficult to diagnose. 

Increased size of the abdomen is the main symptom associated with PMP, but it can also cause pain and discomfort, a hernia, and a change in bowel habits. In this article, we will discuss the main symptoms of PMP, its complications, and when to seek medical assistance.

Shot of a young woman experiencing stomach pain while lying on the sofa at home


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Frequent Symptoms

PMP develops after a small growth (a polyp) located within the appendix (the narrow pouch projecting from the colon, or large intestine) bursts through the wall of the appendix and spreads tumor cells throughout the surrounding surfaces in the area.

When the tumor cells enter your abdomen, more tumors form and make mucinous fluid, a jelly-like material. This eventually fills up your belly, which is why PMP is sometimes referred to as "jelly belly."

Many patients lack symptoms until the disease has reached a relatively advanced stage. The following are some of the commonly reported symptoms:

  • Appendicitis (lower right abdominal pain)
  • Gradual increase in waist size
  • A buildup of fluid in the abdomen called ascites
  • Bloating
  • Change in bowel habits
  • Hernia, when muscles tear or weaken, allowing an organ or fatty tissue to push into an area where it doesn’t belong
  • Ovarian mass or lump

The increased fluid in your abdomen may then compress internal organs, such as reproductive organs, digestive organs, and organs of the urinary system. This may result in abdominal pain.

Rare Symptoms

Bowel obstruction may occur as a consequence of progressive PMP, with the fluid filling your abdominal cavity and compressing your organs. This can lead to intestinal failure and malnutrition, when your body does not get enough nutrients.

Symptoms that often happen before a bowel obstruction include:

  • Decreased appetite
  • Cramping pain or discomfort
  • Bad breath
  • Changes in bowel movements

The most common effects of a bowel obstruction include:

If you are experiencing the symptoms of bowel obstruction, you should seek medical help. Untreated, bowel obstruction can lead to infection and be life-threatening.

Complications/Subgroup Indications

In affected females, the second most common finding is usually an abnormally enlarged ovary. The mucinous tumor seems to grow rapidly within ovarian tissue. When PMP spreads to the ovaries, it may affect fertility (being able to become pregnant). In a small study of women with PMP, infertility was a presenting symptom in three of the four women.

PMP can sometimes be confused with or misdiagnosed as ovarian cancer because ovarian cancer may also cause a swollen abdomen. Some types of ovarian cancer cells also produce mucin. 

In affected males, a common symptom is a protrusion of parts of the intestines through an abnormal opening in the muscular wall of the abdomen near the groin (inguinal hernia).

When to See a Doctor/Go to the Hospital

PMP is fairly rare but appendicitis (inflammation of the appendix) is a condition that needs medical attention. Once it starts, there is no effective medical therapy, so appendicitis is considered an emergency. Symptoms of appendicitis may include:

  • Pain in the abdomen, first around the navel, then moving to the lower right area—this is called migratory abdominal pain
  • Loss of appetite
  • Nausea and vomiting
  • Constipation or diarrhea
  • Inability to pass gas
  • Low fever that begins after other symptoms
  • Abdominal swelling
  • Indigestion

Typically, appendix pain worsens when moving, taking deep breaths, coughing, or sneezing. The area that is painful becomes very tender to pressure.

The most serious complication of appendicitis is a rupture. The appendix bursts or tears if appendicitis is not diagnosed quickly and goes untreated. A ruptured appendix can lead to infection and abscess, a painful collection of pus caused by the infection. In a few patients, complications of appendicitis can lead to organ failure and even death.

Summary

PMP is a slow-growing cancer and, as such, symptoms may take many months or even years to develop. When symptoms do occur, they are usually related to the buildup of mucinous fluid in the abdomen and can include bloating, pain, and a change in bowel habits.

A Word From Verywell

If you have a slowly increasing waist size with no obvious reason and if you are experiencing changes in your bowel habits or notice a hernia develop, speak to your healthcare provider to rule out PMP.

PMP is rare, but other conditions involving the appendix also require medical attention and should not be ignored.

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5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Disney BR, Karthikeyakurup A, Ratcliffe J, et al. Palliative parenteral nutrition use in patients with intestinal failure as a consequence of advanced pseudomyxoma peritonei: a case seriesEur J Clin Nutr. 2015;69(8):966-968. doi:10.1038/ejcn.2015.97

  3. Sheehan LA, Mehta AM, Sawan S, et al. Preserving fertility in pseudomyxoma peritonei, a novel approachPleura Peritoneum. 2017;2(1):33-36. doi:10.1515/pp-2016-0024

  4. NORD (National Organization for Rare Disorders). Pseudomyxoma peritonei. Updated 2018.

  5. National Institute of Diabetes and Digestive and Kidney Diseases. Appendicitis