Solid Omental Tumors Workup

  • Author: Kendrix J Evans, MD; Chief Editor: John Geibel, MD, DSc, MA   more...
 
Updated: Nov 28, 2011
 

Laboratory Studies

  • Standard preoperative lab studies include coagulation evaluation, CBC, and electrolytes.
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Imaging Studies

  • Most patients undergo abdominal ultrasound as a first-line screening imaging study. Ultrasound can indicate the presence of a mass in the mid abdomen and can differentiate cystic tumors from solid tumors. However, it usually cannot identify the primary site of the tumor and its characteristics. Therefore, an abdominal CT scan is the study of choice in helping to diagnose omental tumors.
  • CT scans provide anatomical details and usually identify the primary tumor site. CT scans may also demonstrate displacement or compression on adjacent organs. In one review of primary omental leiomyosarcomas, all 3 cases revealed CT scan findings of a flat, pancakelike mass with multiple cystic spaces with enhancement of the solid areas of the masses.[25] The masses were located in the anterior compartment of the abdomen, usually anterior to the small bowel loops and transverse colon. This differs from the CT scan appearance of omental metastatic disease, which has been described as an "omental cake" owing to the thickened tumor-implanted omentum floating in ascites.
  • MRI is another available modality that can aid in differentiating cystic tumors from solid tumors. MRI is not operator dependent and requires no preparation contrast medium; however, it is more time consuming and expensive than other imaging modalities.
  • When a GIST is suspected, imaging with 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (FDG-PET) can complement contrasted CT in helping to differentiate benign tissue from malignant tissue and necrotic scar from active tumor. Baseline PET is recommended prior to initiating treatment with imatinib, because 80% of patients will exhibit response based on PET images.
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Other Tests

  • Angiography can be helpful in patients with a suspected omental tumor.
    • The major arterial blood supply of the greater omentum is largely from the right and left gastroepiploic arteries, which are derived from the gastroduodenal and splenic arteries. Knowledge of these vascular structures helps in diagnosing an omental tumor.
    • Malignant tumors are favored when angiography demonstrates a hypervascular mass with neovascularity.
    • Angiography should be performed to determine the feeding artery of the tumor as well as its vascularity.
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Diagnostic Procedures

  • FNA and core needle biopsies are controversial as diagnostic procedures (see Indications).
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Histologic Findings

Primary omental tumors with the following histologic types have been reported:

  • Leiomyosarcoma
  • Fibrosarcoma
  • Hemangiopericytoma
  • Schwannoma
  • Spindle cell sarcoma
  • Liposarcoma[26, 27]
  • Leiomyoma
  • Lipoma
  • Fibroma
  • Mesothelioma
  • Cysts
  • Lipoblastoma
  • Leiomyoblastoma[2]

Liposarcomas are further classified into 4 different subtypes: myxoid, round-cell, well-differentiated, and pleomorphic.[26, 27] The difference between benign and malignant omental tumors depends on the evaluation of many parameters (eg, size, pleomorphism, mitotic activity, necrosis, metastasis). Benign and malignant lesions are almost equally distributed.

Omental GISTs have positive staining for CD 117 (c-kit proto-oncogene protein product), which are present in the interstitial cells of Cajal (ICCs). ICCs are the pacemaker cells that are important for gastrointestinal tract motility. Omental GISTs also are positive for vimentin during immunohistochemical staining. Vimentin is a protein found in cells of mesenchymal origin.

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Contributor Information and Disclosures
Author

Kendrix J Evans, MD  General Surgery Resident, Keesler Military Medical Center, USAF

Kendrix J Evans, MD is a member of the following medical societies: American College of Surgeons, American Medical Association, American Medical Student Association/Foundation, Association of Military Surgeons of the US, and Christian Medical & Dental Society

Disclosure: Nothing to disclose.

Coauthor(s)

Quintessa Miller, MD  Staff Physician, Department of General Surgery, Keesler Air Force Base Medical Center

Quintessa Miller, MD is a member of the following medical societies: American College of Surgeons and National Medical Association

Disclosure: Nothing to disclose.

A Letch Kline, MD  Program Director, Department of Surgery, Keesler USAF Medical Center; Clinical Assistant Professor, Department of Surgery, Uniformed Services University of the Health Sciences, F Edward Hebert School of Medicine

A Letch Kline, MD is a member of the following medical societies: American College of Chest Physicians, American College of Surgeons, American Medical Association, American Society for Parenteral and Enteral Nutrition, Association for Surgical Education, Southeastern Surgical Congress, and Southwestern Surgical Congress

Disclosure: Nothing to disclose.

Specialty Editor Board

Juan B Ochoa, MD  Assistant Professor, Department of Surgery, University of Pittsburgh School of Medicine; Medical and Scientific Director, HCN, Nestle Healthcare Nutrition

Disclosure: Nothing to disclose.

Francisco Talavera, PharmD, PhD  Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Medscape Salary Employment

David L Morris, MD, PhD, FRACS  Professor, Department of Surgery, St George Hospital, University of New South Wales, Australia

David L Morris, MD, PhD, FRACS is a member of the following medical societies: British Society of Gastroenterology

Disclosure: RFA Medical None Director; MRC Biotec None Director

Paolo Zamboni, MD  Professor of Surgery, Chief of Day Surgery Unit, Chair of Vascular Diseases Center, University of Ferrara, Italy

Paolo Zamboni, MD is a member of the following medical societies: American Venous Forum and New York Academy of Sciences

Disclosure: Nothing to disclose.

Chief Editor

John Geibel, MD, DSc, MA  Vice Chair and Professor, Department of Surgery, Section of Gastrointestinal Medicine, and Department of Cellular and Molecular Physiology, Yale University School of Medicine; Director, Surgical Research, Department of Surgery, Yale-New Haven Hospital

John Geibel, MD, DSc, MA is a member of the following medical societies: American Gastroenterological Association, American Physiological Society, American Society of Nephrology, Association for Academic Surgery, International Society of Nephrology, New York Academy of Sciences, and Society for Surgery of the Alimentary Tract

Disclosure: AMGEN Royalty Consulting; ARdelyx Ownership interest Board membership

References

  1. Ishida H, Ishida J. Primary tumours of the greater omentum. Eur Radiol. 1998;8(9):1598-601. [Medline].

  2. Hertzanu Y, Mendelsohn DB, Murray JF. Leiomyoblastoma of the omentum. A case report. S Afr Med J. Aug 21 1982;62(9):297-8. [Medline].

  3. Kimura H, Maeda K, Konishi K, Tsuneda A, Tazawa K, Earashi M, et al. Primary leiomyosarcoma arising in the lesser sac: report of a case. Surg Today. 1997;27(7):672-5. [Medline].

  4. Mahon DE, Carp NZ, Goldhahn RT Jr, Schmutzler RC 3rd. Primary leiomyosarcoma of the greater omentum: case report and review of the literature. Am Surg. Mar 1993;59(3):160-3. [Medline].

  5. Matsuo S, Susumu S, Tsutsumi R, Azuma T, Obata S, Hayashi T. Glomus tumor of the omentum: a case report. J Surg Oncol. Dec 1 2007;96(7):633-6. [Medline].

  6. Naik R, Baliga PB, Pai MR, Nayak KS, Shankarnarayanan. Benign teratoma of the lesser omentum--a case report. Indian J Pathol Microbiol. Jul 2003;46(3):461-3. [Medline].

  7. Ruan CW, Lee CL, Yen CF, Wang CJ, Soong YK. A huge 6.2 kilogram uterine myoma coinciding with omental leiomyosarcoma: case report. Changgeng Yi Xue Za Zhi. Dec 1999;22(4):639-42. [Medline].

  8. Rye BA, Christiansen E, Larsen LG. Acute bleeding from leiomyoblastoma of the greater omentum. A case report. Tumori. Jun 30 1989;75(3):296-8. [Medline].

  9. Tsutsumi H, Ohwada S, Takeyoshi I, Izumi M, Ogawa T, Fukusato T, et al. Primary omental liposarcoma presenting with torsion: a case report. Hepatogastroenterology. May-Jun 1999;46(27):2110-2. [Medline].

  10. Alam K, Maheshwari V, Sabir F, Haq ME, Siddiqui FA, Mefuzuddin S. Glomus tumor of lesser omentum--a case report. Indian J Pathol Microbiol. Jul 2007;50(3):543-4. [Medline].

  11. Bhandarkar D, Ghuge A, Kadakia G, Shah R. Laparoscopic excision of an omental leiomyoma with a giant cystic component. JSLS. Jul-Sep 2011;15(3):409-11. [Medline]. [Full Text].

  12. Cao L, Hu X, Zhang Y, Sun XT. Omental milky spots in screening gastric cancer stem cells. Neoplasma. 2011;58(1):20-6. [Medline].

  13. Miyazawa M, Naritaka Y, Miyaki A, Asaka S, Isohata N, Yamaguchi K, et al. A low-grade myofibroblastic sarcoma in the abdominal cavity. Anticancer Res. Sep 2011;31(9):2989-94. [Medline].

  14. Niwa K, Hashimoto M, Hirano S, Mori H, Tamaya T. Primary leiomyosarcoma arising from the greater omentum in a 15-year-old girl. Gynecol Oncol. Aug 1999;74(2):308-10. [Medline].

  15. Baviskar BP, Dongre SD, Karle RR, Sewlikar VN. Teratoma of lesser omentum in a male infant. J Postgrad Med. Oct-Dec 2006;52(4):304-5. [Medline]. [Full Text].

  16. Hebra A, Brown MF, McGeehin KM. Mesenteric, omental, and retroperitoneal cysts in children: a clinical study of 22 cases. South Med J. Feb 1993;86(2):173-6. [Medline].

  17. O'Brien JG, Allen JE, Queen TA. Leiomyoma of the omentum in a child. J Pediatr Surg. Nov 1986;21(11):981-2. [Medline].

  18. Imachi M, Tsukamoto N, Tsukimori K, Funakoshi K, Nakano H, Shigematsu T, et al. Malignant hemangiopericytoma of the omentum presenting as an ovarian tumor. Gynecol Oncol. Nov 1990;39(2):208-13. [Medline].

  19. von Mehren M, Watson JC. Gastrointestinal stromal tumors. Hematol Oncol Clin North Am. Jun 2005;19(3):547-64, vii. [Medline].

  20. Ishida J, Ishida H, Konno K, Komatsuda T, Abe K. Primary leiomyosarcoma of the greater omentum. J Clin Gastroenterol. Mar 1999;28(2):167-70. [Medline].

  21. Rao SR, Rao RS, Sampat MB. Hemangiopericytoma of greater omentum. Indian J Gastroenterol. Jan-Mar 2000;19(1):33-5. [Medline].

  22. Shiba H, Misawa T, Kobayashi S, Yokota T, Son K, Yanaga K. Hemangiopericytoma of the greater omentum. J Gastrointest Surg. Apr 2007;11(4):549-51. [Medline].

  23. Lipper S, Nunnery EW, Jones KL. Pedunculated fibrosarcoma. Unusual presentation of an intraabdominal fibrosarcoma arising from the greater omentum. Am J Surg. Sep 1980;140(3):457-61. [Medline].

  24. Beebe MM, Smith MD. Omental lipoblastoma. J Pediatr Surg. Dec 1993;28(12):1626-7. [Medline].

  25. Lee JT, Kim MJ, Yoo KS, Suh JH, Leong HJ. Primary leiomyosarcoma of the greater omentum: CT findings. J Comput Assist Tomogr. Jan-Feb 1991;15(1):92-4. [Medline].

  26. Kadow C, Amery AH. Primary liposarcoma of the omentum: a rare intra-abdominal tumour. Br J Clin Pract. Dec 1989;43(12):460-2. [Medline].

  27. Okajima Y, Nishikawa M, Ohi M, Fukumoto Y, Kuroda K, Shimomukai H. Primary liposarcoma of the omentum. Postgrad Med J. Feb 1993;69(808):157-8. [Medline].

  28. Wong PP, Yagoda A. Chemotherapy of malignant hemangiopericytoma. Cancer. Apr 1978;41(4):1256-60. [Medline].

  29. Dodd GD 3rd, Greenler DP, Confer SR. Thoracic and abdominal manifestations of lymphoma occurring in the immunocompromised patient. Radiol Clin North Am. May 1992;30(3):597-610. [Medline].

  30. Schwartz RW, Reames M, McGrath PC, Letton RW, Appleby G, Kenady DE. Primary solid neoplasms of the greater omentum. Surgery. Apr 1991;109(4):543-9. [Medline].

 
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Diagram of subdivisions of the omentum. The greater omentum is attached to the caudal border of the greater curvature of the stomach and consists of the hepatoduodenal, gastrocolic, and gastrosplenic ligaments. The lesser omentum is divisible into 2 parts: the hepatogastric ligament and the hepatoduodenal ligament.
The anterior double-layered fold of the greater omentum descends from the stomach and the first part of the duodenum in front of the small intestine and ascends behind itself as far as the transverse colon.
Table. Distribution of Primary Omental Tumors
Tumor HistologyNumber of Cases% of Total
Leiomyosarcoma2217
Hemangiopericytoma86
Sarcoma32
Myosarcoma21.5
Fibrosarcoma32
Reticulosarcoma11
Spindle cell sarcoma11
Liposarcoma11
Rhabdomyosarcoma11
Leiomyoma/leiomyoblastoma1411
Lipoma54
Fibroma32
Fibromatosis21.5
Mesothelioma21.5
Endothelioma11
Myxoma11
Neurofibroma11
Malignant fibrous histiocytoma11
Gastrointestinal stromal tumor2116
Glomus21.5
Teratoma2821
Lipoblastoma86
Total131100
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