FAQs

PMP is an abbreviation for Pseudomyxoma Peritonei. Pseudomyxoma Peritonei is a rare condition characterized by the presence of mucin-producing tumors (and the mucin) in the abdominal cavity. There are a number of possible origins of PMP, but the most common source is appendiceal (appendix) cancer. Classifications of PMP vary based upon several factors including the malignancy of the tumors and the slow or aggressive growth pattern of the tumors and mucin, among other factors. The widely accepted general spectrum of classifications of PMP:

• Dissemenated Peritoneal Adenomucinosis (DPAM)
• “Hybrid” Peritoneal Mucinous Carcinomatosis with Intermediate Features (PMCA-I)
• Peritoneal Mucinous Carcinomatosis (PMC/PMCA)

 
PMP is also sometimes referred to as a "Peritoneal Surface Malignancy" (PSM).

Estimates vary, but all tend to be within the range of “extremely rare.” PMP was once thought to be diagnosed in about 1000 people world-wide each year; in other words, the lifetime odds of being diagnosed with PMP are about 1 in 1 million. However, specialists now believe it is more common than was once thought – possibly due to prior misdiagnosis or misclassification.

PMP is listed among the rare or "orphan" diseases acknowledged by the National Association of Rare Disorders (NORD). An orphan disease is generally considered to have a prevalence of fewer than 200,000 affected individuals in the United States.

Orphan diseases such as PMP have such a low prevalence in the general population that a doctor in a busy general practice is unlikely to see more than one case a year (if any). It also means that most pathologists see the disease infrequently and may misinterpret cell pathology, resulting in an incorrect diagnosis. Patients would benefit from improved awareness and diagnostic methods in the medical community through earlier detection and treatment of PMP.

There are a number of theories about the origins of PMP, but there is no known underlying cause. It is generally accepted that appendix cancer is the most common source of the tumors that cause PMP. Cells from a mucinous tumor in the appendix leak into the abdominal cavity and implant on the peritoneum or other abdominal organs. These tumors replicate and produce a mucinous byproduct that spreads throughout the abdomen.

Specialists and researchers have cited the ovary, stomach, colon, pancreas and other abdominal organs as other potential sites of origin.

Many patients lack clearly defined symptoms until the disease has reached a relatively advanced stage. The following are some of the commonly reported symptoms:

• Increased abdominal girth
• Bloating
• Pain/discomfort in the abdominal region—can be a dull ache or sharp pains similar to appendicitis
• Hernia symptoms—PMP is often initially diagnosed as a hernia, especially in men
• In women, symptoms of an ovarian cyst or tumor—PMP is often initially misdiagnosed as ovarian cancer
• Ascites (fluid) buildup in the abdominal cavity

 

For most patients PMP is considered treatable, but not curable. There are, however, a growing number of individuals—primarily those whose disease was detected early and with favorable pathology—who have undergone cytoreductive surgery and HIPEC and experienced years of disease-free survival.

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