Diagnostic Ultrasound - Abdomen and Pelvis

Solid Peritoneal Mass
– Higher density ascites
– Smooth peritoneal thickening
– No omental cake
Helpful Clues for Rare Diagnoses
• Primary Malignant Peritoneal Tumors
○ Papillary Serous Carcinoma
– Postmenopausal women with elevated CA125
– Imaging appearance and histology closely mimic
metastatic papillary serous ovarian carcinoma, but
with much worse prognosis
– Ovaries are normal with at most surface involvement
by tumor
– Extensive calcification in up to 30%
○ Desmoplastic Small Round Cell Tumor
– Highly aggressive malignancy of adolescents and
young adults
– Multiple hypoechoic, round bulky peritoneal masses ±
internal necrosis ± ascites
• Carcinoid
○ Arises within bowel wall; strong fibrotic reaction of
mesentery causing radiating appearance of mesenteric
vessels on color Doppler study
• Benign Mesenchymal Tumors
○ Leiomyomatosis peritonealis disseminata primarily
affects reproductive-age females
– Absence of ascites and omental cake
○ Mesenteric plexiform neurofibroma in NF1 is most
common manifestation
○ Solitary fibrous tumor
– Rare, usually benign spindle cell neoplasm
– Well-defined, hypervascular soft tissue mass
• Tumor-Like Conditions
○ Desmoid Tumor: Benign, locally aggressive proliferative
process with tendency to recur locally; irregular solid
hypoechoic mass
– 30% have mesenteric infiltration; 13% of these
patients have Gardner syndrome
○ Castleman Disease: Hypertrophic lymphadenopathy ±
hypervascular soft tissue masses; foci of coarse
calcification (5-10%); hepatosplenomegaly
○ Inflammatory pseudotumor: Idiopathic chronic
inflammatory disorder, children and young adults
– Omental and mesentericmasses or infiltration,
increased vascularity, ± tiny calcifications
○ Splenosis: History of splenic rupture or splenectomy
– Multiple small solid nodules, similar to spleen, no
ascites, peritoneal thickening or omental cake
○ Sclerosing mesenteritis
– Idiopathic condition; variants: Mesenteric panniculitis
and retractile mesenteritis
– Soft tissue masses with varying amounts of echogenic
fat with shadowing ± calcification
○ Omental infarction/epiploic appendagitis
– Vascular compromise to omentum or epiploic
appendage respectively
– Hyperechoic tender fat containing "mass"
○ Endometriosis
– Women of childbearing age
– Fibrotic implants on bowel serosa, adhesions,
endometriomas
○ Gliomatosis peritonei
– Implantation of glial tissue on peritoneum from
rupture of teratoma, ventriculoperitoneal shunt, or
metaplasia
– Masses, peritoneal thickening, omental cake, ascites
• Systemic Diseases
○ Extramedullary Hematopoiesis
– Infiltrative form (spleen, liver, mesentery) > mass-like
form (paraspinal)
– Hypoechoic, hypovascular masses
○ Systemic Amyloidosis: Rarely multifocal or diffuse
mesenteric infiltration, dystrophic Ca++ important clue
but not always present
Differential Diagnoses:
Abdominal Wall/Peritoneal Cavity
Peritoneal Carcinomatosis
Peritoneal Carcinomatosis
(Left) Transverse ultrasound of
the right lower quadrant in a
patient with a history of
perforated colon carcinoma
shows a heterogeneous
peritoneal metastasis ſt
lateral to ileum st. (Right)
Longitudinal color Doppler of
the pelvis in a patient with
endometrial cancer shows an
ovarian metastasis ſt and
surrounding ascites st. A
fibroid is also noted .
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