Diagnostic Ultrasound - Abdomen and Pelvis

Peritoneal Carcinomatosis
Diagnoses: Abdominal Wall/Peritoneal Cavity
• Similar to carcinomatosis: Thick nodular masses involving
anterior parietal peritoneum, becoming confluent and
cake-like
• Large solid omental and mesenteric masses often
infiltrating bowel and mesentery
• Smaller volume of ascites
• Look for associated pleural calcification (sign of asbestos
exposure)
Peritoneal Tuberculosis
• Ileocecal mural thickening, matted, hypoperistaltic small
bowel loops, necrotic lymph nodes, splenomegaly, or
splenic calcifications favor tuberculosis
• Wet type (90%): Ascites with increased density ±
mesenteric nodes
• Fixed fibrotic type (7%): Smooth thickening of peritoneum,
nodular mesenteric masses, loculated ascites ± calcification
• Dry type (3%): Peritoneal fibrosis
Peritoneal Sarcomatosis
• Peritoneal spread of sarcoma most commonly from
gastrointestinal stromal tumors, liposarcoma, and
leiomyosarcoma
• Discrete well-defined masses with more smooth outlines,
typically > 2 cm
• Less ascites, peritoneal thickening, omental cake, serosal
implants, and lymphadenopathy than carcinomatosis
Peritoneal Lymphomatosis
• Rare peritoneal spread of lymphoma, typically aggressive
non-Hodgkin (diffuse large B cell most common)
• Bulky omental thickening or smooth peritoneal nodules
(typically > 5 cm), less ascites
• Lymphadenopathy, mesenteric masses ("sandwiching"
vessels), and splenomegaly help distinguish from
carcinomatosis and sarcomatosis
• Intense FDG uptake, nodular or diffuse
PATHOLOGY
General Features
• Etiology
○ Metastatic disease to peritoneal surfaces, omentum, and
mesentery
○ Most commonly from ovarian, colorectal, gastric, breast
and pancreatic cancer
– Less common: Lung and renal carcinoma
○ Sarcomas and lymphomas may also spread
intraperitoneally
• Genetics
○ Colorectal, endometrial, and ovarian cancers related to
Lynch syndrome
Staging, Grading, & Classification
• Peritoneal metastases indicate stage IV disease (excluding
ovarian carcinoma)
Gross Pathologic & Surgical Features
• Infiltrating masses of peritoneal surfaces, omentum, and
mesentery
• Omental cake: Replacement of omental fat by tumor and
fibrosis
• Ascites: Clear or turbid and thick (viscous/gelatinous)
Microscopic Features
• Varies according to primary tumor
○ Most commonly adenocarcinoma
CLINICAL ISSUES
Presentation
• Most common signs/symptoms
○ Abdominal distension and pain, weight loss, malaise,
fever
• Other signs/symptoms
○ Progression of known malignancy
• Clinical profile
○ New presentation: Diagnosis may be made by
paracentesis or tissue sampling of mass
○ May have elevated tumor markers such as CA125 or CEA
Demographics
• Age
○ Adults generally > 40 years
○ Younger patients with hereditary syndromes
• Gender
○ More common in females than males, due to ovarian
carcinoma
Natural History & Prognosis
• Variable, depending on primary tumor; poor prognosis in
general
• Progressive if untreated
• Complication: Bowel obstruction
Treatment
• Depends on pathology
• Cytoreductive surgery ± hyperthermic intraperitoneal
chemotherapy
• Combination of systemic and intraperitoneal
chemotherapy
DIAGNOSTIC CHECKLIST
Consider
• Peritoneal sarcomatosis if there are large, well-defined
smooth, intraperitoneal masses with no omental
involvement and minimal ascites
• Peritoneal lymphomatosis if there are also large mesenteric
and retroperitoneal nodal masses and splenomegaly
• TB peritonitis if there is ileocecal involvement, necrotic, or
calcified lymph nodes
SELECTED REFERENCES
1. Wasnik AP et al: Primary and secondary disease of the peritoneum and
mesentery: review of anatomy and imaging features. Abdom Imaging.
40(3):626-42, 2015
2. Diop AD et al: CT imaging of peritoneal carcinomatosis and its mimics. Diagn
Interv Imaging. ePub, 2014
3. O'Neill AC et al: Differences in CT features of peritoneal carcinomatosis,
sarcomatosis, and lymphomatosis: retrospective analysis of 122 cases at a
tertiary cancer institution. Clin Radiol. 69(12):1219-27, 2014
4. Vicens RA et al: Multimodality imaging of common and uncommon
peritoneal diseases: a review for radiologists. Abdom Imaging. ePub, 2014
5. Cabral FC et al: Peritoneal lymphomatosis: CT and PET/CT findings and how
to differentiate between carcinomatosis and sarcomatosis. Cancer Imaging.
13:162-70, 2013
6. Oei TN et al: Peritoneal sarcomatosis versus peritoneal carcinomatosis:
imaging findings at MDCT. AJR Am J Roentgenol. 195(3):W229-35, 2010
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