Summary: An 80-year-old female with a history of unknown malignancy presents with worsening abdominal fullness
axial computed tomography (CT) images demonstrate a large volume of peritoneal
fluid with a mass effect on the bowel, scalloping of the liver edge, and right-sided
hydronephrosis. Several surgical clips are present in the right side of the
pelvis. A large hiatal hernia, midline ventral abdominal hernia, and pleural
effusions are also present.
peritonei refers to intraperitoneal accumulation of gelatinous ascites. It
occurs secondary to rupture of a well-differentiated mucinous adenocarcinoma of
the appendix. Previously it was thought that psuedomyxoma peritonei could also
be due to mucinous tumors of the ovary, but now it is thought to be more likely
that the ovarian lesions are metastatic.
Patients most commonly present
with abdominal pain, distention, weight loss, and often demonstrate new onset
of abdominal hernias secondary to mass effect. As the accumulation of mucin
progresses, patients may develop bowel obstructions as well as ureteral
Imaging findings of
pseudomyxoma peritonei include accumulation of low-attenuation fluid through
the peritoneum, omentum, and mesentery. Some of the fluid may demonstrate
loculations, and cystic structures may be identified on ligaments, such as the
falciform and gastrohepatic ligaments. As the gelatinous fluid accumulates, it
exerts mass effect on surrounding structures and will often scallop the surface
of visceral organs such as the liver and less commonly the spleen. Hernias may
also develop as the intraabdominal pressure increases. Ultrasound evaluation
reveals echogenic peritoneal fluid and echogenic mucinous intraperitoneal
masses. Magnetic resonance imaging (MRI) evaluation will demonstrate low-signal
fluid on T1-weighted images and high-signal fluid on T2-weighted images. Cystic
implants may also be seen on MRI. As expected, findings of scalloping of the
edges of visceral organs as well as abdominal hernias may be appreciated by
both ultrasound and MRI.
Pseudomyxoma peritonei is a
progressive disease, which is treated with surgical debulking and
intraperitoneal chemotherapy. Despite treatment, gelatinous ascites
reaccumulates over time with worsening symptoms and is ultimately fatal.
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