Pseudomyxoma Peritonei



Pseudomyxoma Peritonei


R. Brooke Jeffrey, MD









(Left) Axial CECT in a 62-year-old man with a history of appendiceal carcinoma, now presenting with progressive abdominal distension and partial bowel obstruction, demonstrates massive, loculated ascites. Note the scalloped surface of the liver and spleen image due to peritoneal tumor implants. (Right) Axial CECT in the same patient reveals that the cystic or gelatinous metastases are also evident as omental masses image.






(Left) Axial CECT in a 61-year-old man with recent resection of an appendiceal carcinoma, now presenting with abdominal distension, shows a classic scalloped surface of the liver and spleen due to loculated mucinous collections of malignant ascites image. (Right) Axial CECT in the same patient reveals the presence of an ileostomy image, which was required because the loculated mucinous peritoneal metastases resulted in compression, distortion, and partial obstruction of the bowel.



TERMINOLOGY


Abbreviations



  • Pseudomyxoma peritonei (PMP)


Definitions



  • Diffuse intraperitoneal accumulation of gelatinous ascites due to rupture of well-differentiated mucinous adenocarcinoma of appendix



    • Rarely due to rupture of other mucinous tumors of colon, stomach, pancreas, gallbladder, fallopian tube


    • Ovary was previously thought to be primary site, but ovarian lesions are now thought to be metastatic from appendiceal primary


IMAGING


General Features



  • Best diagnostic clue



    • Scalloping of liver and spleen contour by low-attenuation masses


  • Location



    • Often diffuse throughout peritoneal cavity


    • Along mesenteries and ligaments


    • Extensive peritoneal involvement common


    • Subphrenic spaces



      • Perihepatic and perisplenic locations most common


  • Size



    • Cystic implants vary in size


  • Morphology



    • Gelatinous low-attenuation masses


Radiographic Findings



  • Radiography



    • Evidence of ascites


    • Lateral displacement of liver margin


    • Lateral displacement of cecum


    • Pelvic “dog’s ears”



      • Lobulated fluid collections in pelvis on either side of urinary bladder


    • Displacement of bowel loops centrally within abdomen

Jun 8, 2016 | Posted by in GENERAL RADIOLOGY | Comments Off on Pseudomyxoma Peritonei
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