see also:

• neoplasia / cancer / tumours

• pseudomyxoma peritonei (PMP) is a rare slowly growing mucin-producing tumor in the abdomen and pelvis which often starts in the appendix but can also rarely arise from mucinous tumors of other sites such as the colon, stomach, pancreas, lung, breast, gallbladder, fallopian tubes, or ovaries

• rare
  • 1-4 cases per million people per year
  • 22 cases per million population
• mainly in those over aged 40yrs
  • median age at diagnosis is around 48-53 years
• women are slightly more likely than men to have it

• poorly understood risk factors
• does not seem to be familial although it may be in 10% of cases
• no clear risk factors have been identified

• genetic mutations such as in the KRAS gene have been implicated in the oncogenesis of PMP
• most cases arise from a mucinous neoplasm of the appendix that ruptures, spreading mucus-producing cells throughout the peritoneal cavity, provoking the characteristic mucin accumulation and peritoneal implants

• rarely spreads but does cause pressure on other organs which can be symptomatic
• increasing waist size
• abdominal or pelvic pains
• altered bowel habits
• bloating
• anorexia
• hernia

• generally incidentally found on CT scan of abdomen
• diagnosis may be confirmed by biopsy

• small tumors are generally actively monitored
• may need repeated debulking surgery
• cytoreductive surgery followed by chemotherapy may be an option
• radiotherapy may be an option