Abdominopelvic Tumors and Masses (Abdomen and Pelvis)

Question 1

Associated with asbestos exposure

This lesions demonstrates nodular, irregular peritoneal omental thickening and masses in CT

Which merge to large plaques and cake-like thickenong of the omentum, “omental cake”

Answer 1

Peritoneal mesothelioma

US - sheet-like superficial mass

Question 2

In peritoneal metastasis

What are the preferential sites for tumor implantation?

Answer 2

Pelvic cul-de-sac
Right paracolic gutter
Greater omentum

Question 3

CT scan finding of peritoneal metastases

Answer 3

1. Tumor nodules on peritoneal surfaces
2. “omental caking”
3. Tumor nodules in the mesentery
4. Thickening and nodularity of the bowel wall due to serosal implants
5. Ascites (lobulated)

Question 4

Extramedullary hematopoiesis occurs when the primary sites of hematopoiesis in the bone marrow fail

What are its possible causes?

Answer 4

Myelofibrosis

Hemolytic anemias overwhelm blood cell production (sickle cell disease and thalassemia)

Question 5

Most obvious/common manifestation of extramedullary hematopoiesis in CT scan

Answer 5

Homogeneous, well-marginated paraspinal masses the favor the thoracic spine

Bilateral, symmetric and enhance mildy

Question 6

Most common sarcoma of the retroperitoneum

Answer 6

Sarcoma

Question 7

This is a rare condition manifest by formation of fibrous plaque in the lower retroperitoneum that encases and compresses the aorta, inferior vena cava, and ureters

Answer 7

Retroperitoneal fibrosis

Question 8

15% of retroperioneal fibrosis have other fibrosing processes which are?

Answer 8

Mediastinal fibrosis
Riedel fibrosisng thyroiditis
Sclerosing cholangitis
Fibrotic orbital pseudotumors

Question 9

Fibrotic plaques of retroperitoneal fibrosis are usually located where?

Answer 9

Over the anterior surfaces of the L4 and L5 vetebrae

Question 10

Hallmark of retroperioneal fibrosis

Answer 10

Smooth extrinsic narrowing of one or both ureters in the region of L4-5