You are in: eMedicine Specialties > Pediatrics: Surgery > General Surgery Mesenteric and Omental CystsArticle Last Updated: Jan 16, 2008AUTHOR AND EDITOR INFORMATIONSection 1 of 11
  Author: Amulya K Saxena, MD, Attending Pediatric Surgeon, Department of Pediatric Surgery, Medical University of Graz, Austria Amulya K Saxena is a member of the following medical societies: European Pediatric Surgeons Association, German Society of Pediatric Surgery, German Society of Surgery, and International Pediatric Endosurgery Group Editors: Kurt D Newman, MD, Vice Chairman, Department of Pediatric Surgery, Children's National Medical Center; Professor, Departments of Surgery and Pediatrics, George Washington University School of Medicine; Mary L Windle, PharmD, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy, Pharmacy Editor, eMedicine.com, Inc; Deborah F Billmire, MD, Associate Professor, Department of Surgery, Indiana University Medical Center; H Biemann Othersen Jr, MD, Professor of Surgery and Pediatrics, Emeritus Head, Division of Pediatric Surgery, Medical University of South Carolina; Harsh Grewal, MD, FACS, FAAP, Professor of Surgery and Pediatrics, Temple University School of Medicine; Chief, Section of Pediatric Surgery, Temple University Children's Medical Center Author and Editor Disclosure Synonyms and related keywords: mesenteric cysts, omental cysts, cyst, abdominal cyst, intra-abdominal cyst, abdominal mass, chylous mesenteric cyst, cystic hygromas, abdominal distention, ascites, intestinal volvulus, dilated bowel, intestinal atresia, dilated stomach, pyloric atresia, gastrointestinal duplications, hydronephrosis, ovarian cyst, cystic teratoma, inguinal hernia, intestinal duplication cyst INTRODUCTIONSection 2 of 11
  History of the ProcedureIn 1907, the Italian anatomist Benevieni first reported a mesenteric cyst following an autopsy on an 8-year-old girl.1 In 1842, von Rokitansky described a chylous mesenteric cyst.2 Gairdner published the first report of an omental cyst in 1852.3 Tillaux performed the first successful surgery for a cystic mass in the mesentery in 1880.4 FrequencyMesenteric and omental cysts are rare; the incidence is about 1 per 140,000 general hospital admissions and about 1 per 20,000 pediatric hospital admissions.5, 6, 7 In a study from Egleston Children's Hospital at Emory University from 1965-1994, 14 patients were treated for mesenteric or omental cysts, which represents a prevalence of about 1 case per 11,250 admissions.8 Approximately one third of cases occur in children younger than 15 years.9, 10, 11 The mean age of children affected is 4.9 years.9, 11, 12, 13, 14, 15, 16 Mesenteric cysts are 4.5 times more common than omental cysts.17 EtiologyAs proposed by Gross, mesenteric and omental cysts are thought to represent benign proliferations of ectopic lymphatics that lack communication with the normal lymphatic system.9, 18, 19 Cysts are thought to arise from lymphatic spaces associated with the embryonic retroperitoneal lymph sac, making them analogous to cystic hygromas, which arise in the neck in association with the jugular lymph sac.20 Another proposed etiology is lymphatic obstruction;21 however, experimental occlusion of lymphatic channels in animals does not produce mesenteric or omental cysts because of the rich collaterals in the lymphatic system, which sheds doubt on this particular theory.6, 18, 20 Other etiologic theories include (1) failure of the embryonic lymph channels to join the venous system, (2) failure of the leaves of the mesentery to fuse, (3) trauma, (4) neoplasia, and (5) degeneration of lymph nodes.8 Mesenteric cysts can occur anywhere in the mesentery of the gastrointestinal tract from the duodenum to the rectum, and they may extend from the base of the mesentery into the retroperitoneum.8, 6 In a series of 162 patients, 60% of mesenteric cysts occurred in the small-bowel mesentery, 24% in the large-bowel mesentery, and 14.5% in the retroperitoneum. They most commonly occur in the ileal mesentery of the small bowel or the sigmoid mesentery of the colon.5 Omental cysts are confined to the lesser or greater omentum.22 PathophysiologyMesenteric and omental cysts can be simple or multiple, unilocular or multilocular, and they may contain hemorrhagic, serous, chylous, or infected fluid.8 The fluid is serous in ileal and colonic cysts and is chylous in jejunal cysts.7, 11 They can range in size from a few millimeters to 40 cm in diameter. In a series from Egleston Children's Hospital in Atlanta, the mean size was 14.9 X 11.5 X 4.7 cm.8 ClinicalMesenteric and omental cysts can be discovered as an incidental finding during laparotomy for another condition or they can manifest as an acute life-threatening intra-abdominal catastrophe.22 Children generally present with abdominal distention and few associated symptoms other than vague abdominal pain with or without a palpable mass.21 The mass may be huge, simulating ascites.22 The most common mode of acute presentation in children is that of a small-bowel obstruction, which may be associated with intestinal volvulus or infarction.11, 13, 15 In the series from Egleston Children's Hospital in Atlanta, 21% of patients were asymptomatic, 71% presented with abdominal distention, 50% with abdominal pain, 50% with vomiting, and 43% with a palpable abdominal mass.8 Approximately 10% of patients with mesenteric and omental cysts present with an acute abdominal emergency.22 These masses can be detected using prenatal ultrasonography and appear as a sonolucent mass. The prenatal differential diagnosis includes dilated bowel (eg, intestinal atresia), dilated stomach (eg, pyloric atresia), gastrointestinal duplication, hydronephrosis, ovarian cyst, and cystic teratoma. In a series of 82 children who underwent surgery for various causes of intestinal volvulus, mesenteric cysts were the underlying etiology in 3.65% of cases.23 A very unusual presentation of a mesenteric cyst is that of an irreducible inguinal hernia.1 The differential diagnosis includes intestinal duplication cyst; ovarian, choledochal, pancreatic, splenic, or renal cysts; hydronephrosis; cystic teratoma; hydatid cyst; and ascites.22 INDICATIONSSection 3 of 11
In children, the most common indication for surgical intervention is the presence of an abdominal mass with or without signs of intestinal obstruction. Various complications have been associated with mesenteric and omental cysts, including intestinal obstruction (most common), volvulus, hemorrhage into the cyst, infection, rupture, cystic torsion, and obstruction of the urinary and biliary tract.22 Malignant transformation of mesenteric cysts has occurred in adults,5 but malignant mesenteric and omental cysts have not been reported in children.22 RELEVANT ANATOMYSection 4 of 11
Mesenteric cysts most commonly occur in the small-bowel mesentery on the mesenteric side of the bowel. Mesenteric cysts can often be shelled out from between the leaves of the mesentery while taking care to avoid damage to the mesenteric vessels,21 or they may require concomitant bowel resection in order to ensure that the blood supply to the bowel is not compromised.22 In a series from Egleston Children's Hospital in Atlanta, one third of patients required intestinal resection along with resection of the mesenteric cysts.8 WORKUPSection 5 of 11
Lab Studies
Imaging Studies
Other Tests
Diagnostic Procedures
Histologic FindingsCystic lymphangiomas are sometimes differentiated from mesenteric and omental cysts.6, 9, 15 Cystic lymphangiomas have an endothelial cell lining, foam cells, and thin walls that contain lymphatic spaces, lymphoid tissue, and smooth muscle. Mesenteric cysts lack smooth muscle and lymphatic spaces, and the cells lining the cysts are cuboidal or columnar in nature.6 Lymphangiomas are more diffuse and occur in the mesentery or retroperitoneum, and patients may present earlier in life than those with mesenteric or omental cysts.6, 15 In a series of 191 patients with lymphangioma, 4.7% of patients presented with lymphangioma in the mesentery.26 For the purposes of this discussion, a mesenteric cyst is defined as any cyst that is located in the mesentery and may or may not extend into the retroperitoneum; a mesenteric cyst also has a recognizable lining of endothelial or mesothelial cells. An omental cyst has the same histologic characteristics but is confined to the greater or lesser omentum.22 TREATMENTSection 6 of 11
Medical therapyNo medical therapy is available. Surgical therapyThe goal of surgical therapy is complete excision of the mass. Omental cysts can be removed without endangering the adjacent bowel.9, 13, 14 The preferred treatment of mesenteric cysts is enucleation,5, 7, 14, 21 although intestinal resection is frequently required to ensure that the remaining bowel is viable. Bowel resection may be required in 50-60% of children with mesenteric cysts, whereas resection is necessary in about one third of adults.5, 9, 11, 13, 15 Any resulting mesenteric defect must be closed to prevent an internal hernia. If enucleation or resection is not possible because of the size of the cyst or because of its location deep within the root of the mesentery, the third option is partial excision with marsupialization of the remaining cyst into the abdominal cavity.22 Approximately 10% of patients require this form of therapy.5 If marsupialization is performed, the cyst lining should be sclerosed with 10% glucose solution,10 electrocautery, or tincture of iodine to minimize recurrence. Partial excision alone with or without drainage is not indicated because of the high recurrence rate associated with these procedures.5 Preoperative detailsThe patient should undergo standard preoperative preparation for a major laparotomy. This includes inserting a nasogastric tube, initiating intravenous fluid therapy, and beginning prophylactic antibiotics preoperatively in the event that a bowel resection is required. If time allows, the patient should undergo mechanical bowel preparation for the same reason. Intraoperative detailsMesenteric cysts can be shelled out from between the leaves of the mesentery using fine electrocautery, taking care not to damage the blood vessels to the adjacent intestine. If this is not feasible, a standard bowel resection with a primary end-to-end anastomosis is performed. Intestinal diversion is not necessary unless gross peritonitis from a long-standing bowel perforation is present. Omental cysts are excised by removing the involved portion of the mesentery up to the transverse colon if necessary. In the vast majority of cases, removing the adjacent colon or stomach is not necessary.13, 14 Postoperative detailsThe patient is maintained nothing by mouth (NPO) with intravenous fluids and nasogastric suction until bowel function returns. Prophylactic antibiotics can be discontinued after 1-2 postoperative doses. If the patient is not able to eat by the third postoperative day, parenteral nutrition should be provided. Follow-upRoutine postoperative follow-up care 2-3 weeks after discharge from the hospital is indicated. The child's family should be warned about the potential for intestinal obstruction from adhesions. If the patient was treated with marsupialization, closer follow-up for possible recurrence should be instituted. Otherwise, no long-term follow-up for surgical problems is necessary. COMPLICATIONSSection 7 of 11
Complications from surgery, either early or late, are uncommon.8 Complications associated with mesenteric and omental cysts are discussed above. OUTCOME AND PROGNOSISSection 8 of 11
Overall results in pediatric patients are favorable. The recurrence rate ranges from 0-13.6%,9, 11, 14, 15, 17 averaging about 6.1% in a series of 162 adults and children.5 Most recurrences occur in patients with retroperitoneal cysts or those who had only a partial excision.5, 14, 15, 17 Essentially, no mortality is associated with mesenteric or omental cysts in children; only one pediatric death has been reported since 1950.27 In a series from Egleston Children's Hospital in Atlanta, no major postoperative complications, recurrences, or deaths occurred.8 FUTURE AND CONTROVERSIESSection 9 of 11
With the widespread use of prenatal ultrasonography, mesenteric and omental cysts are being diagnosed in utero.22 No role for treating these cysts in utero is recognized. If cysts are discovered prenatally, intervention during early infancy is indicated to prevent potential complications such as obstruction and intestinal volvulus. MULTIMEDIASection 10 of 11
REFERENCESSection 11 of 11
Mesenteric and Omental Cysts excerpt Article Last Updated: Jan 16, 2008 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||
