Mesenteric cyst in infancy: presentation and management

Mesenteric cysts are documented as a rare entity in pediatric population. They are considered as benign intra-abdominal tumors with an unknown etiology. Symptoms are not specific and knowledge of such condition is essential in order to establish a proper management. We report three pediatrics cases of mesenteric cysts managed between 2000 and 2009 in the pediatric surgery Department of Monastir College Hospital. We described the clinical, radiological and operative findings. Two males and a female were managed (age range: 10 days-5years, mean age: 6,3years). Two patients were presented with an intestinal obstruction. A preoperative diagnosis was made basing on imaging. Thus, abdominal ultrasonography was performed in all of our reported cases and showed a cystic mass in all cases. The cystic nature of the mass, its margins and its extension were better described on tomographic images. The mesenteric cyst was completely and successfully removed in all cases. The histopathological report confirmed the diagnosis and showed a multiloculated cyst with columnar mesothelial lining, without any defined muscular layer or cellular atypia and without any evidence of malignancy. The children were evaluated post-operatively with a mean follow-up of 2 years and a half. No recurrence was noted in our patients during the follow-up period. It is known that clinical features are not specific of such anomaly but once the diagnosis is made, the complete surgical removal of the cyst remains the treatment of choice with excellent outcomes.


Case report 1
A 10-day newborn female baby was admitted for an abdominal cystic mass discovered prenatally. On Physical examination, there was a mass of about 7*5cm at the left lower abdomen. Biological tests were unremarkable. A plain X-ray of the abdomen revealed a radio opaque lesion located at the left iliac fossa which compressed adjacent digestive system. The ultrasonography and the CT scan of the abdomen (Figure 1) confirmed the image. They showed a thin-walled, fluid-filled calcified mass measuring 7cm long axis. The baby was operated using a laparoscopic three-trocar approach.
Intraoperatively, the lesion was closely adherent to the sigmoid wall. We performed a complete enucleation of the cyst. The histological report confirmed the diagnosis of calcified mesenteric cyst. cyst required a small bowel resection ( Figure 6). The patient's postoperative recovery was good. The hospital stay was 9 days.

Case report 2
Pathological report of the removed lesion was compatible with a mesenteric cyst.

Discussion
The first case of mesenteric cyst reported in the literature was by Benevieni in 1507 [1,2]. Similar pathogeneses are documented in Mesenteric and omental cysts. They are arising from benign multiplication of ectopic lymphatic chanels lacking communication with the remaining normal lymphatic system [3,4]. Their etiology has not been clearly discovered yet [5]. The mean incidence is estimated at 1 in 100,000 in-patients [4,6]. These benign tumors are unusual causes of intra-abdominal masses in childhood [7,8].
The diagnosis is made before the age of 10 years in 25% [7,9].
The clinical presentation of the lesion depends primarily on the location as well as the size of the cyst. In fact, they can present either with nonspecific abdominal complaints or with acute abdominal pain [7,8]. The clinical presentation depends also on its associated complications. However many of these cases are asymptomatic and diagnosed incidentally [2]. Abdominal pain is documented as the commonest symptom and an acute abdominal presentation revealing a bowel obstruction is often reported in infants. Rarely an abdominal distension or a mass are found on physical examination [2,6]. Our experience revealed that two patients presented with an intestinal obstruction. Complications include torsion, infarction, volvulus formation [2,10,11] similar to what was observed in our third case report. Other complications were also reported like perforation, infection, anemia from intracystic bleeding, and rupture which is a rare condition usually occuring following an abdominal trauma [4,[12][13][14]. Cystic abdominal masses are easily evaluated radiologically by ultrasonography, CT scan and MRI [2,15]. Ultrasound is a very sensitive and specific radiological imaging modality used not only for the diagnosis but also for the follow-up of these cysts, even in the prenatal period [7,16]. Ultrasonography is a sensitive and specific radiological assessement that provide several radiological features of the lesion. Once an abdominal mass is suspected, ultrasonography should be performed for an initial radiological evaluation. It is feasible and reveals fluid filled cystic lesion.
Computed Tomography and Magnetic Resonance Imaging could be helpful and essential in order to obtain a better features description of the mass [4,17]. Additional informations including lesion origin, its relationships and its adhesion to visceral organs, this can be useful if a laparoscopic surgery is considered [18]. Abdominal ultrasonography was performed in all of our reported cases and showed a cystic mass in all cases. An abdominal computed tomography was carried out and confirmed the cystic nature of the mass, its margins and its extension. The management of this disease is generally performed using a mini-invasive surgery [19,20]. Laparoscopic approach is well indicated for pediatric population [7]. In this report one patient was managed using laparoscopic approach. Laparotomy was necessary in the remaining