IS Case 162: Pseudomyxoma peritonei

Daniel Ginat, MD, MS

Imaging Sciences URMC 2008
Publication Date: 2009-05-21


Patient is a 78-year-old female with a history of colon cancer presenting with right-sided back pain.


Diffuse scalloping of the liver and spleen contour. Extensive peritoneal fluid of varying attenuation, which also contains a small amount of gas, likely due to superimposed infection. Peritoneum is diffusely thickened and enhanced.


Pseudomyxoma peritonei

Differential diagnosis includes carcinomatosis, peritoneal sarcomatosis, and infectious peritonitis.


Pseudomyxoma peritonei is a rare condition in which the peritoneal cavity fills with gelatinous material (mucin), associated with implants on the peritoneal surfaces and omentum. The main etiologies include ruptured appendiceal mucocele, intraperitoneal metastasis from ovarian, colon, and occasionally pancreatic adenocarcinomas.

On CT pseudomyxoma peritonei is classically characterized by scalloping of the spleen and liver margins, as demonstrated in this case. There may also be multilocular cystic masses and septa with rims of curvilinear calcifications. While loops of bowel may be displaced centrally, the bowel is relatively spared until late in the disease process. The presence of pneumoperitoneum may suggest superimposed infection.

Overall prognosis for pseudomyxoma peritonei is fair, with a 5-year survival rate approaching 65%. Treatment is mainly surgical, although intraperitoneal chemotherapy may be helpful.


  1. Lee HH, Agha FP, Weatherbee L, Boland CR. Pseudomyxoma peritonei. Radiologic features. J Clin Gastroenterol. 1986 Jun;8(3 Pt 1):312-6. [PMID: 3525659]
  2. Johnson CD, Schmit GD. Mayo Clinic Gastrointestinal Imaging Review. Rochester, MN: Mayo Clinic Scientific Press, 2005.

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