Pseudomyxoma peritonei

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**Pseudomyxoma peritonei**
*Classifications and external resources*
ICD-10	C48.2, C78.6 (ICD-O 8480/6)
ICD-9	197.6

Pseudomyxoma peritonei (PMP, sometimes informally known as "jelly belly") is a very rare form of tumor, commonly known as "jelly belly" due to its production of mucus in the abdominal cavity. The tumor is not harmful by itself, but the mucus has no place to go inside the abdominal cavity. If left untreated, it will eventually build up to the point where it compresses vital structures: the colon, the liver, kidneys, etc.

Unlike most cancers, PMP does not spread through the lymphatic system or through the bloodstream.

It is believed that most PMP starts as cancer of the appendix; the Helicobacter pylori bacterium also seems to be implicated. Mucinous tumors of the ovary have also been implicated.

[edit] Diagnosis

Because it is so rare, it is frequently either not diagnosed or misdiagnosed. Usually the only symptom is of the belly getting bigger, which doctors and patients alike can easily assume is from the patient getting fatter.

Frequently, PMP is diagnosed after the patient is operated on or gets a CT scan for some other problem. On a CT scan, the mucous shows up as a light grey area.

The mucous normally has the consistency and appearance of orange gelatin, but can cement to become much harder.

[edit] Treatment

Because PMP is very rare, there is variation in the treatment.

As the tumor grows very slowly, sometimes people choose to just watch and wait.

The most common treatments are debulking and cytoreductive surgery. With debulking, the surgeon attempts to remove as much tumor as possible.

With cytoreductive surgery, the surgeon takes out the peritoneum and any organs that appear to have tumor on them. If the organ is important, only part of it might be removed. Since the mucus tends to pool at the bottom of the abdominal cavity, it is common to remove the ovaries, fallopian tubes, uterus, and parts of the large intestine. Depending upon the spread of the tumor, other organs might be removed, including but not limited to the gallbladder, spleen, and all or portions of the small intestine and/or stomach. For organs that can not be removed safely (like the liver), the surgeon strips off the tumor from the surface.

It is very important to remove or kill every last cancer cell because the cancer cells reproduce quickly on scar tissue, and there is lots of scar tissue after surgery.

To kill the last few cells, chemotherapy drugs are put directly into the abdominal cavity. Either the drugs are swished around by hand for an hour or two as the last step in the surgery, or ports are installed to allow circulation and/or drainage of the chemicals for one to five days after surgery.

Cytoreductive surgery usually takes between ten and thirteen hours, and is sometimes referred to by patients as MOAS (Mother Of All Surgeries) or as the Sugarbaker Procedure (after the doctor who pioneered this form of treatment).

Even with the most aggressive heated chemotherapy treatment, it is very common to have the tumor come back, so further surgeries are frequently needed. The patients usually get frequent CT scans for a while in order to spot any regrowth of the tumor.

Oral and intravenous chemotherapy is not routinely used, as it not very effective; the tumor does not have a good blood supply and so does not absorb the drugs easily. However, there are some cases in some patients where the tumor growth has been held in check for several years with a combination of orally administered drugs. Additionally recent (2003) publications linking the MUC2 enzyme overexpression to Pseudomyxoma cell reproduction has launched research efforts into additional drug treatments.