1. 88Peritoneal and Omental
Abnormalities

2. CLINICAL IMAGAGING
AN ATLAS OF DIFFERENTIAL DAIGNOSIS
EISENBERG
DR. Muhammad Bin Zulfiqar
PGR-FCPS III SIMS/SHL

3. • Fig GI 88-1 Peritoneal carcinomatosis.
Hematogenous dissemination of malignant
melanoma causes multiple nodules in the
peritoneal space, including the omentum
(arrows), retroperitoneal spaces, and the
subcutaneous fat layer of the abdomen.193

4. • Fig GI 88-2 Tuberculous peritonitis. Large
amount of ascites with even peritoneal
thickening (arrowhead) and diffuse omental
infiltration (arrow) without associated
lymphadenopathy. The initial clinical
impression was carcinomatosis.193

5. Fig GI 88-3 Malignant peritoneal mesothelioma. Diffuse platelike
mass in the greater omentum (arrows), massive ascites, and
peritoneal thickening.193

6. • Fig GI 88-4 Pseudomyxoma peritonei. (A) Axial
and (B) coronal scans show multiple low-
attenuation masses in the omentum and
peritoneal cavity. There is curvilinear or
punctuate calcifications of the seeding
nodules; scalloping of the liver, spleen, and
stomach; and small bowel adhesions from
mesenteric infiltration.193

7. • Fig GI 88-5 Lymphomatosis. Innumerable seeding
nodules in the peritoneal cavity and omentum
(white arrow) with evidence of ascites. Multiple
enlarged lymph nodes with conglomeration
(black arrows) are seen in the retroperitoneal
spaces.193

8. Fig GI 88-7 Sarcoidosis. Diffuse soft-tissue thickening involving
the mesentery, omentum, and parietal peritoneum.194

9. • Fig GI 88-8 GIST. Large, heterogenous,
omentum-based mass.195

10. Fig GI 88-9 Malignant fibrous histiocytoma. Large, heterogeneous
soft-tissue peritoneal mass.195

11. • Fig GI 88-6 Amyloidosis. Extensive peritoneal
soft-tissue infiltration and multifocal coarse
calcifications.194

12. • Fig GI 88-10 Primary serous papillary
carcinoma. (A) Omental cake in the left lower
quadrant displaces adjacent loops of large and
small bowel. (B) In this lower image, there is
lace-like omental infiltration (large arrow) with
irregular nodular thickening of the
peritoneum (small arrow). The mesenteric fat
is normal and there is no lymphadenopathy or
ascites.196

13. • Fig GI 88-11 Metastasis. Large lobulated mass
(arrows) in the left upper quadrant of the
abdomen representing an exophytic carcinoma
extending directly from the greater curvature of
the stomach.193

14. • Fig GI 88-12 Metastasis. Large, lobulated,
heterogeneous mass in the mid-abdomen,
inferior to the stomach. The thickened
peritoneum (arrow) adjacent to the mass is
suggestive of a malignant lesion, which in this
case was an ovarian carcinoma.193

15. Fig GI 88-13 Lymphangioma. Coronal contrast scan shows a
lobulated cystic mass in the greater omentum inferior to the
gastric antrum.193

16. Fig GI 88-14 Paragonimiasis. Multifocal ill-defined cystic lesions and
several nodules (arrow) in the omentum on the right side of the
abdomen.193

17. • Fig GI 88-15 Omental infarction. Localized
fatty infiltration and congestion with a
secondary mass (arrow) in the right lower
aspect of the anterior abdomen.193

18. • Fig GI 88-16 Foreign-body granuloma. Large, well-
circumscribed mass with dense calcification in the anterior
mid-abdomen, an appearance suggestive of a foreign-body
granuloma or organizing hematoma. After contrast
injection, the mass showed no enhancement. The patient
had a palpable mass for 10 years that developed soon after
a Caesarian section.193

19. • Fig GI 88-17 Ventral hernia. Sagittal scan shows herniation
of omental fat through a defect (arrow) in the anterior
abdominal wall. Focal ill-defined lesions with increased
attenuation (arrowheads) in the omental fat adjacent to
the abdominal wall defect are suggestive of omental fat
infarction secondary to vascular compromise.193

20. • Fig GI 88-18 Sclerosing encapsulating
peritonitis. (A, B) Sequential images show
dilated small bowel loops in the center of the
abdomen encapsulated within thick fibrous
membranes (arrows).197

21. • Fig GI 88-19 Inflammatory pseudotumor. The
huge mass suggests a peritoneal
malignancy.194