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Pseudomyxoma Peritonei

NORD is very grateful to Paul H. Sugarbaker, MD, FACS, FRCS, Director, Program in Peritoneal Surface Malignancy, Washington Hospital Center, for assistance in the preparation of this report.

Synonyms of Pseudomyxoma Peritonei

  • colloid carcinoma
  • disseminated peritoneal adenomucinosis (DPAM)
  • malignant appendiceal tumor
  • malignant large bowel cystadenocarcinoma
  • malignant large bowel peritoneal carcinomatosis
  • malignant large bowel tumor
  • mucinous cyst adenocarcinoma
  • mucinous cystadenoma
  • peritoneal carcinomatosis
  • peritoneal mucinous carcinomatosis (PMCA)
  • PMP
  • pseudomyxoma ovarii

Disorder Subdivisions

  • No subdivisions found.

General Discussion

Pseudomyxoma peritonei is a rare malignant growth characterized by the progressive accumulation of mucus-secreting (mucinous) tumor cells within the abdomen and pelvis. The disorder develops after a small growth (polyp) located within the appendix bursts through the wall of the appendix, and spreads mucus-producing tumor cells throughout the surrounding surfaces (e.g., the membrane that lines the abdominal cavity [peritoneum]). As mucinous tumor cells accumulate, the abdominal area becomes swollen and digestive (gastrointestinal) function becomes impaired. Pseudomyxoma peritonei develops at a variable rate, but may grow at a slower rate (indolent) than other malignancies within the abdomen.


The most common symptoms in individuals with pseudomyxoma peritonei occur due to progressively increasing mucinous tumor within the abdomen and pelvis. Usually, the most common symptom is increasing abdominal size (so called "jelly belly") and abdominal pain. Although the abdomen may be swollen, it is generally not painful to touch (palpation). In affected males, the second most common finding is protrusion of parts of the intestines through an abnormal opening in the muscular wall of the abdomen near the groin (inguinal hernia). In affected females, the second most common finding is usually an abnormally enlarged ovary. The mucinous tumor seems to grow rapidly within ovarian tissue.

The mucinous tumor accumulates within the fatty membrane in front of the intestines (greater omentum), beneath the muscle that separates the chest from the abdomen (diaphragm), and within the pelvis. In most cases, the small bowel is unaffected. Frequently, the primary tumor that punctured the appendix may be small in comparison to the extensive mucinous tumor that develops within the abdomen and pelvis. Without treatment intervention, this disorder will result in obstruction of the intestines or the loss of intestinal function. Progressive mucinous tumor accumulation can result in poor food intake, malnutrition, and, eventually, life-threatening complications.


The exact cause of pseudomyxoma peritonei is not known. There are no genetic, familial, or environmental factors known to cause this disorder.

Pseudomyxoma peritonei develops from a hole (perforation) in the appendix that is caused by the penetration of a small growth (polyp) located within the appendix. The tumor cells from the appendix spread (migrate) within the abdominal and pelvic cavity to characteristic locations. Once they reach these locations, tumor cells continue to grow. Characteristic locations for tumor cell growth are within the fatty membrane in front of the intestines (greater omentum), beneath the muscle that separates the chest from the abdomen (diaphragm), and within the pelvis. In females, there may be excessive growth on both ovaries.

Affected Populations

Pseudomyxoma peritonei is a very rare disorder with approximately 500 cases discussed in the medical literature. Males and females are affected in equal numbers. It is a misconception that females develop this disorder more frequently than males. However, this misconception occurs because some ovarian tumors are frequently mistakenly identified as pseudomyxoma ovarii.

The average age of onset of pseudomyxoma peritonei is 48 years, which is considerably earlier than other malignancies that occur within the abdomen.

Related Disorders

Symptoms of the following disorders can be similar to those of pseudomyxoma peritonei. Comparisons may be useful for a differential diagnosis:

An ovarian malignancy known as low malignant potential ovarian tumor may look similar to pseudomyxoma peritonei. However, this tumor remains as a solitary, expanding ovarian mass. It does not distribute itself around the abdomen, and should be distinguishable from pseudomyxoma peritonei. Symptoms may include abdominal or lower back pain. The exact cause of low malignant potential ovarian tumor is not known.

Mucinous cancers of the ovary, colon, stomach, and gallbladder may produce an excess of mucous in the abdominal cavity. These cancers are much more aggressive than the mucinous tumor from the appendix. They result in rapidly progressing accumulation of mucous in the abdominal region and intestinal obstruction. The exact cause of these tumors is not known.

Adenocarcinoid (goblet cell carcinoid) of the appendix is similar to pseudomyxoma peritonei. The mucinous tumor from the adenocarcinoid distributes itself around the abdomen in a very similar fashion to pseudomyxoma peritonei. However, this tumor is much more aggressive than the tumor in pseudomyxoma peritonei. Symptoms of this type of cancer often resemble those of acute appendicitis. The exact cause of adenocarcinoid of the appendix is not known.

Mesothelioma is a rare form of cancer that affects the membrane that covers and protects various internal organs of the body (mesothelium). The mesothelium is composed of two layers of specialized cells known as mesothelial cells. One layer directly surrounds an organ; the other forms a protective sac around the organ. The most common form of mesothelioma affects the membrane or sac that lines the lungs (pleura). Other common sites include the membrane lining the stomach, small bowel and large bowel (peritoneum) and the membrane lining the heart (pericardium). Mesotheliomas may result in a mucinous tumor accumulation within the abdomen that is very difficult to distinguish from pseudomyxoma peritonei. Symptoms of mesothelioma vary depending upon the location, type and stage of the cancer. Approximately 70 to 80 percent of cases of mesothelioma result from exposure to asbestos. Symptoms of mesothelioma may not appear until up to 50 years after initial exposure to asbestos. However, after symptoms began apparent, mesothelioma may rapidly progress to cause life-threatening complications. (For more information on this disorder, choose "mesothelioma" as your search term in the Rare Disease Database.)

Appendicitis is an acute inflammation of the appendix. It is characterized by abdominal pain and inflammation of the lining of the abdominal cavity (appendicitis). The first sign of this condition is an unusual slight discomfort around the navel. Pain typically becomes more intense and localize near the lower right-hand side of the abdomen. Other symptoms of appendicitis may include fever, loss of appetite, vomiting, and abdomen tenderness.

Standard Therapies

The diagnosis of pseudomyxoma peritonei may be confirmed by advanced imaging technologies such as abdominal CT scan or abdominal MRI (magnetic resonance imaging). These imaging tests may reveal the characteristic distribution of large amounts of mucus to particular locations within the abdomen and pelvis. They may also localize a primary tumor at the base of the cecum referred to as a mucocele.

The goal of the treatment of pseudomyxoma peritonei is cure. This is achieved in approximately 65% of patients. The treatments are cytoreductive surgery with peritonectomy in an attempt to remove all visible evidence of the disease from the abdomen and pelvis. Then, to prevent reimplantation of cancer cells, the abdomen is washed with a warm chemotherapy solution. This is commonly referred to hyperthermic intraperitoneal chemotherapy or HIPEC. Sometimes the surgeon must search carefully for the primary appendiceal tumor for it may be very small in comparison to the mucinous tumor and mucinous ascites that can accumulate in kilogram quantities within the abdomen and pelvis. The hyperthermic inrtraperitoneal drugs which are commonly used to treat this disease include mitomycin C and oxaliplatin. The chemotherapy is heated to 42 degress in the abdominal cavity to increase penetration of the drugs into the mucinous tumor and to increase the local cytotoxicity.

Investigational Therapies

Information on current clinical trials is posted on the Internet at All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.

For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222
TTY: (866) 411-1010

For information about clinical trials sponsored by private sources, contact:

Pseudomyxoma Peritonei Resources

NORD Member Organizations:

(To become a member of NORD, an organization must meet established criteria and be approved by the NORD Board of Directors. If you're interested in becoming a member, please contact Susan Olivo, Membership Manager, at

Other Organizations:


Ceelen WP. Peritoneal Carcinomatosis. New York, NY: Springer; 2007.

Sugarbaker P. Cancer of the appendix and pseudomyxoma. In: Current Therapy in Colon and Rectal Surgery. 2nd ed. Philadelphia, PA: BC Decker, Inc; 2005:369-378.

Sugarbaker, P. Intraperitoneal chemotherapy and cytoreductive surgery. 2nd ed. Grand Rapids, MI: Ludann Press:1995.

JO Yan TD, Black D, Savady R, Sugarbaker PH. A systematic review on the efficacy of cytoreductive surgery and perioperative intraperitoneal chemotherapy for pseudomyxoma peritonei. Ann Surg Oncol. 2007;14:484-92.

Sugarbaker PH. New standard of care for appendiceal epithelial malignancies and pseudomyxoma peritonei syndrome. Lancet Oncol. 2006;7:69-76.

Galani E, et al. Pseudomyxoma peritonei: the 'controversial' disease. Int J Gynecol Cancer. 2003;13:413-8.

Van Ruth S, et al. Pseudomyxoma peritonei: a review of 62 cases. Eur J Surg Oncol. 2003;29:682-88.

Jivan S, Bahal V. Pseudomyxoma peritonei. Postgrad Med J. 2002;78:170-72.

Jackson SL, et al. Gelatinous ascites: a cytohistologic study of pseudomyxoma peritonei in 67 patients. Mod Pathol. 2001;14:664-71.

Sugarbaker PH, et al. Pseudomyxoma peritonei syndrome. Adv Surg. 1996;30:233-79.

Gough DB, et al. Pseudomyxoma peritonei: long-term patient survival with an aggressive regional approach. Ann Surg. 1994;219:112-19.

Smith JW, et al. Pseudomyxoma peritonei of appendiceal origin. Cancer. 1992;70:386-401.

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Report last updated: 2012/03/22 00:00:00 GMT+0

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