Omental Cysts in the Pediatric Population: Diagnostic Challenges and Surgical Outcomes

ABSTRACT

Background:

Omental cysts are rare intra-abdominal lymphatic malformations in children, accounting for approximately 2% of all intra-abdominal lymphatic lesions. Their embryological origin remains uncertain, and preoperative diagnosis is often challenging due to their nonspecific clinical and radiological features. This study aims to present our institutional experience with omental cysts in children and review current literature on their presentation, evaluation, and management.

Materials and Methods:

A retrospective review was conducted in our department between 2015 and 2024. Medical records of children who underwent surgery for omental cysts were analyzed for demographic data, presentation, imaging findings, operative details, histopathology, and outcomes.

Results:

Nine children (eight boys, one girl; median age 4 years) underwent omentectomy for omental cysts. Abdominal pain or distension were the most common presentations. Preoperative imaging was suggestive of omental origin in only one child, with others reported as mesenteric cysts or lymphatic malformations. The mean cyst diameter was 14 cm, with laparoscopy attempted in two children, while the rest underwent laparotomy. Histopathology confirmed benign lymphatic malformation in all patients. Postoperative recovery was uneventful, with no recurrence on follow-up for a minimum of 5 years.

Conclusion:

Omental cysts should be considered in the differential diagnosis of cystic abdominal lesions in children. Misdiagnosis as ascites or mesenteric cysts is common. Complete surgical excision through omentectomy remains the treatment of choice, offering excellent outcomes with minimal morbidity and negligible recurrence.

INTRODUCTION

Intra-abdominal lymphatic malformations are rare in children, with an estimated incidence of 1 in 20,000 admissions. Omental cysts comprise just 2% of them.[1] The exact embryological basis for the formation of these cysts is not well known.[2] Clinical presentation ranges from nonspecific abdominal distension to hemorrhage in the cyst, manifesting as an acute abdomen. Preoperative diagnosis is rarely made, and they are commonly mistaken for mesenteric cysts or ascites. Imaging modalities are also inconclusive most of the time.[3] This study aims to highlight our experience with omental cysts in children and review the current literature on their presentation, evaluation, and management.

MATERIALS AND METHODS

A retrospective analysis of electronic medical records spanning 10 years (2015–2024) was conducted in our pediatric surgery department following approval from the institutional review board. The study included nine children who underwent surgery for an omental cyst. Intra-operative findings were noted. Pathology reports of the excised specimens were reviewed, and long-term outcomes were noted. Given the descriptive nature of this retrospective case series and the small sample size, no inferential statistical analyses were performed, and results are presented using descriptive statistics only.

RESULTS

Eight boys and one girl with a median age of 4 years were included in the study [Table 1]. The youngest child was 10 months old. Abdominal pain or distension were the most common presenting symptoms. Ultrasound of the abdomen and pelvis was performed as initial imaging in six children, followed by cross-sectional imaging in all but one. Preoperative imaging suggested an omental origin in only one patient, while the remaining cases were variably reported as mesenteric cysts, lymphatic malformations, or ascites [Figures 1 and 2]. The cyst diameter ranged from 6 to 20 cm, with most lesions being large and necessitating laparotomy. Omentectomy with removal of the cyst was performed [Figure 3]. Histopathology showed findings characteristic of lymphatic malformation. The postoperative period was uneventful. Surgical outcomes were evaluated as short-term postoperative complications following laparotomy and long-term outcomes, including recurrence, adhesive intestinal obstruction, and chylous ascites. The median duration of postoperative follow-up was 5 years, during which no recurrences or late complications were observed.

Table 1.

Summary of the patient details

Case	Age	Gender	Main symptom	Imaging diagnosis	Operative approach	Size of cyst (cm)
1	5 years	Male	Abdominal pain	USG and CT - Lymphatic cyst of unknown origin	Laparotomy	8
2	10 months	Male	Abdominal distension	USG - Complex cystic lesion MRI - Chylolymphatic mesenteric cyst/cystic mesothelioma	Laparotomy	15
3	5 years	Female	Abdominal distension	CT - Mesenteric lymphatic cyst	Laparotomy	15
4	4 years	Male	Abdominal distension	USG - Mesenteric cyst CT - Omental/mesenteric cyst	Laparotomy	18
5	5 years	Male	Abdominal pain	USG - Enteric duplication cyst/mesenteric cyst	Laparotomy	12
6	2 years	Male	Abdominal mass	CT - Mesenteric lymphatic cyst	Laparotomy	15
7	4 years	Male	Abdominal distension	USG - Ascites	Laparoscopy assisted	6
8	2 years	Male	Abdominal distension	USG - ascites CT - Multiloculated cyst of unknown origin	Laparotomy	17
9	2 years	Male	Abdominal distension	USG and CT - Lymphatic cyst of unknown origin	Laparoscopy assisted	20

USG: Ultrasound of abdomen and pelvis, MRI: Magnetic resonance imaging, CT: Computed tomography

Figure 1.

Ultrasound abdomen and pelvis showing a large multi-loculated cystic lesion with internal septations

Figure 2.

Computed tomography of abdomen and pelvis showing a large, well-defined, abdominopelvic loculated cystic lesion with enhancing walls and thin septations: (a) Coronal section in a 2 years; (b) Axial section in a 7-year-old

Figure 3.

Intra-operative image showing multi-loculated cystic lesion arising from the greater omentum

DISCUSSION

Omental cysts are rare intra-abdominal lesions that present more frequently in children than in adults.[4] They are often discussed in conjunction with mesenteric cysts due to their similar embryological origins; however, they are three to ten times less common than mesenteric cysts.[5] The precise etiology is not known, with the most accepted theory being benign proliferation of ectopic lymphatic tissue that fails to establish connections to normal lymphatic systems, resulting in sequestered cystic masses. Incomplete fusion of the mesothelial leaves of the omentum is also postulated as a possible cause.[1]

Clinical presentation patterns

The majority of patients are diagnosed by the time they are 5 years old, with 70% presenting within 10 years.[5] The spectrum of presentation varies depending on the size of the cysts. While small cysts are usually discovered incidentally, large ones commonly present with abdominal pain, abdominal distension, or a palpable mass. They can also present in an acute setting secondary to torsion, hemorrhage, or infection. A review of all the reported cases of omental cysts in children in the literature shows that 20% of them presented with an acute abdomen [Table 2].

Table 2.

Compilation of reported pediatric omental cyst cases with diagnostic and surgical details

Year	Author	Journal	Number of cases	Primary symptom	Imaging diagnosis	Size (cm)	Approach and other intervention
2001	Prasad et al.[10]	Indian journal of pathology and microbiology	2	Abdominal distension	CT - Ascites	1–31 2–20	Laparotomy
2005	Menon and Rao[11]	Indian Pediatrics	1	Abdominal distension	USG and CT - Ascites	-	Laparotomy
2007	Fitoz et al.[4]	Journal of Clinical Ultrasound	1	Abdominal distension	CT - Cystic mass	-	Laparotomy
2009	Shafi et al.[6]	African Journal of Pediatric Surgery	1	Abdominal distension	USG and CT - Ascites	25	Laparotomy *Paracentesis
2010	Nett et al.[12]	Radiology case reports	1	Abdominal distension	CT - Ascites	-	Laparotomy *Paracentesis
2010	Joshi et al.[7]	J Infect Dev Ctries	1	Abdominal distension	USG and CT - Tuberculous ascitis	15	Laparotomy
2012	Gupta et al.[5]	BMJ case reports	1	Abdominal pain	CT - Cystic mass	27	Laparotomy
2012	Nam et al.[3]	Journal of Korean Surgical Society	8	-	-	-	Laparotomy
2013	Ibrahim et al.[13]	Open Journal of Pediatrics	2	Abdominal mass	USG and CT - Ascites CT - Cystic mass	1–15 2–6	Laparotomy *Paracentesis
2013	Adikibi et al.[1]	African Journal of Pediatric Surgery	3	Acute abdomen	*USG - Ascites	17	Laparotomy *Paracentesis
2016	Karhan et al.[8]	Iran Journal of Radiology	1	Abdominal distension	MRI - Tuberculous ascites	25	Laparotomy *Paracentesis
2021	Sayeed et al.[2]	Portuguese Journal of Gastroenterology	1	Abdominal pain	CT - Ascites	19	Laparotomy *Paracentesis
2021	Robbins et al.[14]	Annals of Pediatric Surgery	1	Abdominal pain	USG - Ascites CT - Cystic mass	15	Laparotomy *Paracentesis
2021	Chong et al.[15]	Pan African Medical Journal	1	Abdominal distension	USG - Duplication cyst	5	Laparotomy
2022	Alemu et al.[9]	International Medical Case Reports	1	Acute abdomen	-	20	Laparotomy
2023	Albejais et al.[16]	Cureus	1	Acute abdomen	CT - Cystic mass	8	Laparotomy
2023	Cheng et al.[17]	Frontiers in Medicine	1	Acute abdomen	CT - Hemorrhagic cyst	18	Laparotomy
2024	Mohamed et al.[18]	Journal of Surgical Case Reports	1	Abdominal distension	CT - Cystic mass	30	Laparotomy

*Paracentesis was done prior to surgery due to misdiagnosis of ascites. USG: Ultrasound of abdomen and pelvis, MRI: Magnetic resonance imaging, CT: Computed tomography

Imaging challenges in preoperative diagnosis

Accurate preoperative diagnosis of omental cysts is complex, with overall rates reported to be around 15%, and our review shows <10%.[5] Imaging often reveals a nonspecific cystic mass leading to a broad differential diagnosis that includes mesenteric cysts, retroperitoneal cysts, intestinal duplications, ovarian cysts, and even ascites. The large size makes it technically challenging to determine the exact origin of the cyst.[3] Imaging plays a crucial yet often inconclusive role in the preoperative evaluation of omental cysts. Ultrasonography, the initial imaging modality in most cases, typically demonstrates a thin-walled, fluid-filled cystic lesion that may be unilocular or multiloculated with internal septations. Low-level internal echoes may be present in complicated cysts due to hemorrhage or infection. Cross-sectional imaging with contrast-enhanced computed tomography or magnetic resonance imaging provides better delineation of cyst size, extension, and relationship to adjacent structures; however, precise determination of the site of origin remains challenging, particularly for large lesions.[4]

Common diagnostic pitfalls and misdiagnosis

The most significant and frequently cited pitfall is incorrect diagnosis of “psuedoascites” wherein the large cyst is mistaken for free fluid in the abdomen.[6] This was observed in one-third of the cases reviewed from the literature. Two patients were assumed to have tuberculous ascites.[7,8] This leads to unnecessary procedures and interventions, with paracentesis being done in seven of the twenty-nine reported cases. There was also a delay in the correct diagnosis with complications like hemorrhage in these patients [Table 2].

Surgical approaches and outcomes

Surgery, either laparotomy or diagnostic laparoscopy, provides the final diagnosis in nearly all cases. At our center, the choice of surgical approach is individualized and based on cyst size, suspected origin, clinical presentation, and surgeon experience, as no standardized protocol exists for this rare condition. Although laparotomy was preferred in our series due to the large size of most cysts, there is an increasing trend in the literature toward attempting laparoscopic excision, even for large lesions. Techniques such as percutaneous or intra-operative cyst aspiration to facilitate decompression and the use of traction methods, including hitch stitches, have been described to improve exposure and enable minimally invasive resection. Conversion to open surgery remains an acceptable and safe option when intraoperative challenges arise. Reported advantages of laparoscopy include shorter hospital stay, reduced postoperative pain and morbidity, lower overall costs, and superior cosmetic outcomes. Intra-operatively, a thin-walled, multi-loculated lesion is seen arising from the omentum with either straw-colored or sero-sanguinous fluid as content. None of the reports showed chyle as content. Omentectomy is performed to ensure the complete removal of the cyst.[9]

The histopathological findings in these cases were predominantly benign malformations of the lymphatic system. Chronic inflammatory cells and hemosiderin-laden macrophages may be present, indicating underlying infections or hemorrhage.[2] No malignancy has been reported in children.[5] Postoperative morbidity is minimal, and complications are uncommon. Risk of recurrence in the long term is very low and is primarily attributed to incomplete excision.

The limitations of this study include its small sample size, retrospective design, and single-center nature, which limit generalizability. Preoperative imaging interpretation was not standardized and relied on routine radiology reports. Although no recurrences were observed, variable follow-up duration may have led to underestimation of late recurrence.

CONCLUSION

Omental cysts, though rare, should be considered in the differential diagnosis of cystic abdominal lesions in children. Misdiagnosis and unnecessary interventions can be avoided by greater awareness and improved imaging interpretation. Complete excision through omentectomy ensures excellent outcomes with minimal morbidity and negligible recurrence risk.

Conflicts of interest

There are no conflicts of interest.

Funding Statement

Nil.