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Disease Profile

Pseudomyxoma peritonei

Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.


US Estimated

Europe Estimated

Age of onset





Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease.


Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype.


dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.


recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder.


Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.


Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.


Not applicable


Other names (AKA)

PMP; Syndrome of pseudomyxoma peritonei; Adenomucinosis;


Digestive Diseases; Rare Cancers


Pseudomyxoma peritonei (PMP) is a rare disease characterized by the presence of mucin in the abdominal (peritoneal) cavity. While the most common cause of PMP is appendix cancer, several types of tumors (including non-cancerous tumors) can cause PMP.[1] Signs and symptoms may include an increase in abdominal size or bloating; inguinal hernia (in men); an ovarian mass that may be felt during a routine pelvic exam (in women); pain or discomfort in the abdomen; and/or appendicitis.[1][2] Treatment depends on the underlying cause of the condition (the location and type of the original tumor, including whether it is malignant) and the extent of spreading.[1] A combination of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy is often the most successful treatment.[1][2][3]


This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
80%-99% of people have these symptoms
Abnormality of the abdominal wall
Abnormality of the peritoneum
Accumulation of fluid in the abdomen
30%-79% of people have these symptoms
Inflammation of the large intestine
5%-29% of people have these symptoms
Abdominal pain
Pain in stomach
Stomach pain

[ more ]

Intestinal obstruction
Bowel obstruction
Intestinal blockage

[ more ]

Swollen lymph nodes
Nausea and vomiting
Respiratory insufficiency
Respiratory impairment
Weight loss


The exact cause of pseudomyxoma peritonei (PMP) is currently unknown. No specific genetic or environmental factors have been found to cause PMP.[4] Various types of tumors can lead to PMP, and it is not known why some cause PMP and others do not.[1] Appendix tumors are the most common primary tumors associated with PMP, but tumors of the ovary, colon, stomach, pancreas, and urachus have also been reported in people with PMP.[5]

It is generally thought that cells from a mucinous tumor (usually of the appendix) spread into the abdominal cavity, attaching themselves to the peritoneum and other organs in the abdomen.[1] The tumor cells then continue to grow and produce mucin, which builds up and contributes to the signs and symptoms in people with PMP.[4]


The treatment of pseudomyxoma peritonei depends on the underlying cause of the condition (the location and type of the original tumor, including whether it is malignant) and the extent of spreading.[1] The approach depends on the size of the lesions and damage. It is needed to have an exploratory surgery (laparotomy) to find out which organs are affected. A combination of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy is often the most successful treatment, and can achieve overall survival outcomes of up to 84% at 5 years.[1][2][3] Cytoreductive surgery involves removing all lesions that can be removed. This is followed by hyperthermic intraperitoneal chemotherapy which involves placing heated chemotherapy drugs directly into the peritoneal cavity during surgery to destroy any remaining tumor cells that are too small to be seen.[1][3]

Pressurized intraperitoneal aerosol chemotherapy is another option that can be combined with the surgery and have less complications of the hyperthermic form, but this treatment is still experimental and can be carried out only in specialized centers.The procedure is performed for 90 min under general anesthesia. The chemotherapy is vaporized in the form of an aerosol. Chemotherapy after the surgery may also improve the prognosis. Radiotherapy is not efficient because the tumor is not differentiated.[6]

A good washing of the peritoneal cavity is useful, but the lesions frequently come back. The surgery must remove the appendix, and sometimes even a the right part of the colon, the uterus and the ovaries.[6] 


Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

    Learn more

    These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

    Where to Start

    • The Appendix Cancer/Pseudomyxoma Peritonei Research Foundation has a list of frequently asked questions for those diagnosed with Pseudomyxoma Peritonei (PMP), Appendix Cancer and related Peritoneal Surface Malignancies (PSM), and their caregivers. Click on the link above to view their answers to these questions.
    • Cancer Research UK provides a basic overview of Pseudomyxoma peritonei on their website.
    • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.
    • Pseudomyxoma Survivor is a support network for those affected by PMP, appendix cancer and peritoneal surface malignancies. Click on the link above to view information about Pseudomyxoma peritonei.

      In-Depth Information

      • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
      • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
      • PubMed is a searchable database of medical literature and lists journal articles that discuss Pseudomyxoma peritonei. Click on the link to view a sample search on this topic.


        1. About ACPMP. ACPMP Research Foundation. https://acpmp.org/about-acpmp.
        2. Richard Swanson, Jeffrey A Meyerhardt. Cancer of the appendix and pseudomyxoma peritonei. UpToDate. Waltham, MA: UpToDate; March, 2016;
        3. Tan GH, Novo CA, Dayal S, Chandrakumaran K, Mohamed F, Cecil T, Moran BJ. The modified Glasgow prognosis score predicts for overall and disease-free survival following cytoreductive surgery and HIPEC in patients with pseudomyxoma peritonei of appendiceal origin. Eur J Surg Oncol. October 2016; pii: S0748-7983(16)30947-7:
        4. Pseudomyxoma Peritonei. NORD. 2015; https://rarediseases.org/rare-diseases/pseudomyxoma-peritonei/.
        5. François-Noël Gilly and Olivier Glehen. Pseudomyxoma peritonei. Orphanet. March, 2011; https://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=26790.
        6. Pugin F, Bouquet De Jolinière J, Major A, Khomsi F & cols. Pseudomyxoma Peritonei: A Case Report Diagnosed in a 47-Year-Old Woman with Chronic Pelvic Abdominal Pain and Appendicular Origin: Review of the Literature and Management. Front Surg. December 18, 2017; 4(41):https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5741642/.

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