Omental cakes: unusual aetiologies and CT appearances

Abstract

BACKGROUND: Omental cakes typically are associated with ovarian carcinoma, as this is the most common malignant aetiology. Nonetheless, numerous other neoplasms, as well as infectious and benign processes, can produce omental cakes. METHODS: A broader knowledge of the various causes of omental cakes is valuable diagnostically and to direct appropriate clinical management. RESULTS: We present a spectrum of both common and unusual aetiologies that demonstrate the variable computed tomographic appearances of omental cakes. CONCLUSION: The anatomy and embryology are discussed, as well as the importance of biopsy when the aetiology of omental cakes is uncertain.

Fig. 1

Schematic sagittal diagram demonstrating the anatomy of the greater omentum (Modified and reprinted with permission from [2])

Fig. 2

(a,b). Adenocarcinoma of the vulva in a 55-year-old woman. a Gross omental cake specimen with an 8-cm irregular firm nodular lesion at the superior border. b Transverse sections of the omentum show that the lesion is solid, tan-white with scattered foci of hemorrhage (arrow)

Fig. 3

(a,b). Ovarian cancer in a 47-year-old woman demonstrating progresssion of omental cake. a Initial CT image shows early infiltration and nodularity of the omentum (arrows) and retroperitoneal adenopathy (arrowheads). b Interval progression of disease with ascites and the mass-like omental cake (arrowheads) in the remaining omentum after a partial omentectomy on a CT scan 3 months later

Fig. 4

Ovarian cancer in a 51-year-old woman. CT image shows extensive omental thickening (arrows) and ascites

Fig. 5

Colon cancer in a 65-year-old man. CT image demonstrates a thick omental cake in the left anterior abdomen (arrows). Peripheral ascites is also present, predominantly on the right side

Fig. 6

Pancreatic adenocarcinoma in a 58-year-old man. CT image shows multiple, ill-defined, soft tissue nodules and masses (arrows) permeating the omental fat. Ascites is also present in the right paracolic gutter

Fig. 7

Gastric cancer in a 53-year-old woman. CT image demonstrates diffuse linear infiltration, nodularity, and thickening of the omentum (arrows)

Fig. 8

Renal cell carcinoma in a 62-year-old man. CT image shows extensive soft tissue nodules present within the omentum (arrows) and the retroperitoneum. A right nephrectomy with surgical clips is seen in the right renal fossa, and ascites is also seen on the right

Fig. 9

Gallbladder carcinoma in a 70-year-old woman. CT image illustrates an omental cake anterior to the liver with infiltration and nodularity of the omental fat (arrows). The tumour also infiltrates the fat of the lesser sac (arrowheads)

Fig. 10

Cholangiocarcinoma in a 56-year-old man. CT image shows omental involvement with infiltration and nodules (arrows). A biliary stent is also present (arrowhead). Splenomegaly is present

Fig. 11

Fallopian tube carcinoma in a 45-year-old woman. CT image demonstrates omental involvement (arrows) as infiltration of the fat, nodularity, and coalescence of the nodules form an omental cake

Fig. 12

Endometrial adenocarcinoma in a 50-year-old woman. CT image shows multiple nodular metastases present within the omentum (arrows) and along the peritoneal surface, the result of intraperitoneal seeding. Hepatomegaly and retroperitoneal metastases are present

Fig. 13

Prostate cancer in a 75-year-old man. CT image demonstrates omental infiltration (arrows) seen in the absence of ascites or other signs of peritoneal carcinomatosis. Note is made of an inferior vena cava filter

Fig. 14

Urothelial carcinoma of the bladder in a 59-year-old man. CT image shows extensive diffuse omental involvement (arrows), including the surfaces of the adjacent bowel

Fig. 15

Breast cancer in a 45-year-old woman. CT image illustrates peritoneal carcinomatosis with ascites, peritoneal thickening, nodularity (curved arrow), and omental cake (arrowheads). Note also the shrunken liver (arrows) with pseudocirrhosis appearance seen after treatment for liver metastases from breast cancer

Fig. 16

Non-small cell lung cancer in a 65-year-old man. CT image demonstrates hematogenous metastases seeding the omentum as seen in this omental cake (arrows) adjacent to the spleen and left upper quadrant. There are small bilateral pleural effusions

Fig. 17

Non-Hodgkin’s lymphoma in a 70-year-old man. CT image shows omental cakes (arrowheads) manifested as ill-defined areas of soft tissue anteriorly and peripherally in the abdomen. Multiple renal cysts and calcified gallstones are present, as is ascites

Fig. 18

Primary mesothelioma in a 52-year-old man. CT image shows a thin omental cake (arrows) in the anterior abdomen with a small amount of ascites in the left paracolic gutter and perihepatic spaces

Fig. 19

Testicular mesothelioma in a 53-year-old man. CT image shows an omental cake (arrows) in the anterior abdomen

Fig. 20

Gastrointestinal stromal tumour (GIST) in a 45-year-old man. CT image shows large, cystic-appearing masses (arrows), some involving the omentum, and a large volume of ascites. The patient had been treated with imatinib mesylate (Gleevec; Novartis, New York, NY) that led to the cystic changes. There is a subcutaneous implant in the right anterior abdominal wall

Fig. 21

Liposarcoma in a 56-year-old man. CT image demonstrates multiple, clustered, nodular metastases present within the omentum seen in the right abdomen (arrows)

Fig. 22

Tuberculosis in a 51-year-old man. CT image demonstrates ascites and large, low-attenuation omental macronodules covered with a thin omental line (arrows)

Fig. 23

41-year-old woman with AIDS, an ovarian mass, and omental cake: CT fluoroscopic-guided percutaneous biopsy of the omental thickening using a 22-g needle revealed Actinomyces israelii, but no evidence of malignancy

Fig. 24

Coccidioidomycosis in a 43-year-old woman. CT image shows an omental nodule in the right anterior abdomen (arrow) and mesenteric lymph nodes (arrowheads). (Courtesy of Dr. Arash Heidari)

Fig. 25

Myelofibrosis in a 66-year-old man with a history of splenectomy. CT image shows extensive omental infiltration (arrows) with areas of nodularity and ascites. Oral contrast is noted in bowel loops. Biopsy revealed extramedullary hematopoiesis. Benign omental cakes are indistinguishable from those caused by malignancy

Fig. 26

Unknown primary cancer and omental cake in a 65-year-old man. CT fluoroscopic-guided biopsy of the omental cake using a 22-g needle (arrow) revealed adenocarcinoma, with the primary being in the colon