Symptoms of Pseudomyxoma Peritonei

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Pseudomyxoma peritonei (PMP) is a slow-growing (indolent) type of abdominal cancer. Since it is indolent, PMP does not cause symptoms for a long time. The first symptom of this condition is usually a swollen belly, caused by a buildup of mucin (abundant macromolecular proteins found in mucus) in the abdominal cavity and pelvis.

This article will discuss the common symptoms of PMP, rare symptoms, and complications.

Person feeling symptoms of abdominal pressure

Thanit Weerawan / Getty Images

Frequent Symptoms

PMP typically is caused by the eruption of a polyp (a tumor that may be benign) from the appendix into the abdominal cavity lining (peritoneum). This leads to the spread of mucus-producing tumor cells and a gelatinous substance called mucin. This process is slow. It can take many years before PMP symptoms start to occur.

As mucin accumulates, the abdomen and waist get bigger. This is sometimes referred to as “jelly belly.” Abdominal pressure and discomfort are common results. External pressure, such as palpating (pressing on) the abdomen, does not usually cause additional pain.

In people with testes, the second most common symptom of PMP is an inguinal hernia, in which the intestine bulges through a weak spot in the abdominal wall near the groin. In people with ovaries, the second most common symptom is an enlarged ovary.

Other symptoms can include loss of appetite and a change in bowel habits (frequency of defecation).

PMP is a rare cancer diagnosed in one in three people out of a million annually. If you have PMP symptoms, see your healthcare provider for a definitive diagnosis.

It's possible you have a more common, noncancerous condition with similar symptoms. These include lactose intolerance (difficulty digesting a sugar found in dairy products) and irritable bowel syndrome (disorder of the large intestine). Cancers that have similar symptoms to PMP include mesothelioma (cancer of the thin tissue layer covering most internal organs) and mucinous cancers of the ovary, stomach, gallbladder, and colon.

Complications/Subgroup Indications

If PMP is left untreated, serious complications may occur from advanced disease. They include:

  • Infertility in females
  • Bowel obstruction
  • Compression of internal organs
  • Malnourishment
  • Acute appendicitis (inflammation of the appendix) symptoms such as pain, nausea, and vomiting

Superinfected PMP is a very rare complication that may cause intra-abdominal sepsis (the body’s extreme, life-threatening response to infection). Symptoms of superinfected PMP include:

  • Fever
  • Tender, painful abdomen
  • Slightly elevated heart rate (tachycardia)
  • Bloating
  • Nausea

When to See a Healthcare Provider/Go to a Hospital

Untreated PMP can result in serious, life-threatening complications. It’s important to see your healthcare provider if you have symptoms that might be caused by PMP.

PMP is often diagnosed during an exam for another condition. If, however, you notice changes in your body that may be caused by this condition, such as a swollen stomach or unrelenting pressure in your abdomen, let your healthcare provider know.

People with PMP sometimes mention, in retrospect, that they could feel mucin moving around in their stomachs. Some people also mention they experienced what they thought was weight gain, even though their eating habits did not change.

If you have appendicitis-like symptoms or bowel obstruction symptoms, call 911 or go to a hospital immediately.

Appendicitis symptoms include:

  • Abdominal pain or tenderness, often on the right side
  • Vomiting
  • Loss of appetite
  • Fever and chills
  • Changes in bowel movements, including constipation and diarrhea
  • Trouble passing gas

Bowel obstruction symptoms include:

  • Unable to have a bowel movement
  • Inability to pass gas
  • Reduced appetite
  • Loud stomach noises
  • Severe cramping or pain
  • Vomiting

Summary

Pseudomyxoma peritonei (PMP) is a rare type of abdominal cancer. The most common symptom of this condition is a swollen stomach, caused by a buildup of mucin. Abdominal pressure is also a common symptom.

PMP is usually diagnosed once the disease has become advanced. If you have PMP symptoms, let your healthcare provider know. Common PMP symptoms are often caused by other, less serious illnesses. If you do have PMP, it is important to seek treatment. This will help you avoid complications, which may be serious or life-threatening.

A Word From Verywell

PMP is a rare condition. Even so, if you suspect that your symptoms may be caused by PMP, see your healthcare provider. You know your body better than anyone else. If something feels off, finding out what's going on is an important step. No matter the cause of your symptoms, a healthcare provider can help you with treatment and relief.

7 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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