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Q&A: Treatment for Rare Appendix Tumor

Pseudomyxoma peritonei (PMP) is a rare condition originating from the appendix that can be fatal over time. It is easily misdiagnosed, but when discovered, it often can be treated with highly specialized surgery.

Shedding light on this unusual condition is Paul Mansfield, M.D., a professor in
MD Anderson’s Department of Surgical Oncology, who has specialized in treating the condition for 15 years.

Is PMP cancer?

PMP is considered a cancer because it is a tumor that has abnormal cells. However, it does not behave like most cancers, which may spread through the bloodstream or the lymphatic system. The tumor usually has few cells; however, they may make large amounts of mucin, a sticky substance like Jell-O, that over time and repeated operations, may cause blockages of the intestine that can lead to death.

In most cases, the tumor will originate from the appendix, but can start in the ovary, and less commonly the colon or pancreas.

How do you describe PMP to a patient?

It’s a rare condition in which the tumor cells that have spread around the abdominal cavity produce mucous. Over time, these cells produce excessive mucous that collects in the abdomen forming a jelly-like substance called mucin.

When inflammation or tumor cells build up near the opening to the colon, the appendix may expand and rupture like a balloon filled with too much water. The mucus-secreting cells spread throughout the abdomen and may attach to the liver, spleen, diaphragm, uterus and ovaries, and less commonly, the intestines.

PMP is commonly classified in two groups:

Disseminated Peritoneal Adenomucinosis (DPAM) – Consisting of just a few tumor cells and large amounts of mucin.

Peritoneal Mucinous Adenocarcinoma (PMC) – Consisting of more malignant appearing tumor cells with less mucin and a poorer prognosis.

Who does PMP affect?

A review of literature on the topic was published in 2001 in the journal Gynecologic and Obstetric Investigation.

The report determined that:

  • 75% of patients with PMP are female*
  • Average age range is in the mid-50s

*The patient ratio at MD Anderson is 50% men and 50% women.

Approximately 1,000 people in the United States are diagnosed with mucinous appendiceal neoplasms each year. At MD Anderson, we’ve seen more than 250 patients in the last 15 years and currently are seeing about 50 patients each year.

What are typical symptoms?

Some patients have no symptoms, while others may have:

  • Weight gain
  • Abdominal or pelvic pain
  • Abdominal swelling
  • Nausea and vomiting
  • Fatigue
  • Changes in bowel function

How is PMP diagnosed?

The disease is challenging to diagnose. A lot can be hidden inside the abdomen, and it develops slowly over time. Many patients are originally misdiagnosed with ovarian cancer (women) or metatastatic colon cancer.

A diagnosis often occurs unintentionally during:

  • A CT scan for another reason
  • Hernia repair
  • Laparoscopic removal of the gallbladder

What is the treatment for PMP?

Radical surgery is the typical treatment required for PMP. It involves complete surgical removal of the tumor (cytoreduction), combined with a 90-minute treatment in which surgeons continuously rock the patient’s body by hand after filling the abdominal cavity with heated chemotherapy. This technique aids in evenly distributing the drug to help eliminate microscopic disease.

The entire operation usually takes 8-12 hours.

The treatment includes:

  • An incision from the breast bone to pubic bone
  • Debulking – Removal of the large abdominal tumor
  • Removal of mucin-affected areas, possibly including the:
  • Omentum, part of the abdominal cavity
  • Lining of the diaphragm
  • Spleen, gallbladder, uterus and ovaries
  • Right colon, appendix or other portions of the intestines

Patients also may be treated using a “watch and wait” approach, only involving surgery to treat life-threatening complications such as bowel obstruction.

How do you prepare patients for this surgery?

People who plan to undergo this intense surgery must be medically and psychologically ready for it.

To prepare, patients are encouraged to:

  • Read the materials provided by their physician
  • Talk with other patients
  • Donate blood for transfusion
  • Receive vaccinations if splenectomy is possible

Cytoreduction requires the patient to be prepped in the hospital the day before surgery. An epidural catheter is placed to help patients manage the pain they will feel after surgery.

How difficult is the recovery from surgery?

We typically tell patients they will spend three days in the intensive care unit, three weeks in the hospital, but it will be at least three months before they begin to feel like returning to normal activities.

Recovery requires:

  • Assistance with nutrition via a feeding tube
  • Managing soreness and pain
  • Assistance from a caregiver

What is the survival outlook?

With treatment, an estimated:

  • 80% of patients survive five years
  • 60% of patients survive 10 years

Treatment is particularly beneficial in controlling symptoms; however, recurrence of PMP is not uncommon. Many patients may undergo additional surgery to treat the disease. Although PMP is rare, the number of physicians who specialize in treating it throughout the world is increasing through a better understanding of the disease.


© 2015 The University of Texas MD Anderson Cancer Center