Mesenteric Chylolymphatic Cyst of Terminal Ileum in a Child: A Case Report

Introduction

A chylolymphatic cyst is an extremely uncommon kind of mesenteric cyst.^1,2 These cysts, lined by either mesothelium or endothelium, contain a mixture of lymphatic and chylous fluid.^2,3 Chylolymphatic cysts are exceedingly rare, despite mesenteric cysts being more commonly documented in the pediatric population.^2,3

The clinical presentation ranges from asymptomatic cases to signs of intestinal obstruction. Although ultrasound and CT imaging can identify a cystic lesion, a definitive preoperative diagnosis is often not possible.³ 

Case Report

A four-year-old boy presented with pain in the abdomen, fever and vomiting for the past two days. There was a history of recurrent abdominal pain and fever. On per abdominal examination, mild tenderness in the umbilical region was noted. A mobile, soft mass measuring 10X9 cm was palpable within the iliac fossa on the right, extending toward the umbilical and right lumbar regions. Ultrasonography revealed a hypoechoic cystic lesion. Subsequent abdominal CT imaging demonstrated a cystic, hypodense lesion with fluid attenuation in right lower abdomen, compared to the small intestine.

Intraoperatively, a 15 X 10 cm cyst was identified arising from the terminal ileum mesentery, adjacent to the ileal wall. Enlarged lymphatic vessels were seen entering the chylolymphatic cyst (Figure 1 & 2). Milky white fluid (Figure 2) was present in the cyst consistent with the chylolymphatic cyst diagnosis. The chylolymphatic cyst was surgically removed, and the resection of adjacent involved ileum and ileo-ileal anastomosis was performed (Figure 3 & 4). Histopathology revealed aggregates of lymphoids in the cyst wall confirming the diagnosis. The postoperative period was uneventful. At follow-up visits conducted at 3 months and 6 months, the patient remained symptom-free.

Discussion 

Mesenteric cysts are uncommon, with an incidence ranging from 1 in 100,000 to 1 in 250,000 admissions. Chylolymphatic cysts represent a particularly uncommon subtype of mesenteric cysts.^1,3,4

Chylolymphatic cysts arise from ectopic or sequestered lymphatic tissue within the small intestine's mesentery, which enlarges due to the accumulation of chyle and lymph. This buildup arises from a fluid imbalance between inflow and outflow within the lymphatic systems.^3,4

Chylolymphatic cysts could be asymptomatic or may present with symptoms such as abdominal discomfort, distension, lumpiness, or obstruction in the intestines.³ In the present case, patient reported with obstructive symptoms like pain in abdomen, fever and vomiting.

Although less specific, abdominal radiographs can reveal a gasless, homogenous mass displacing adjacent bowels. In cases of intestinal obstruction, dilated bowel loops with air-fluid levels may be observed. This can result from compression of the bowel by a cystic lesion or from mesenteric volvulus. Abdominal ultrasound may reveal a cystic structure associated with the intestines. Chylolymphatic cysts are characterized by a fluid-fluid level, with the heavier lymph settling in the lower level and the lighter chyle forming the upper layer.^6,7 The fluid attenuation and its correlation with the surrounding structures and the chyle-lymph fluid level are better depicted on the CT images.⁷ In our patient, both ultrasound and CT imaging identified a lesion of cysts in the ileal region; however, a definitive preoperative a chylolymphatic cyst diagnosis could not be established.⁵

Various surgical approaches have been employed in the treatment, including percutaneous aspiration, drainage, marsupialization, enucleation, sclerotherapy, and removal of the cyst with or without removal of the affected gut.^8-13 However, drainage and marsupialization of the mesenteric cyst are associated with high recurrence rates, making complete excision in addition to excision of the adjacent bowel the preferred treatment.^11,12 In this case, excision of the chylolymphatic cyst along with the excision of the affected adjacent ileum was performed, followed by ileo-ileal anastomosis.

In the pediatric age group, chylolymphatic cysts should be taken into account in the differential diagnosis abdominal masses of cysts. Thorough removal of the cyst and resection of the adjacent bowel and anastomosis, remains the most effective treatment.

Conflict of Interest

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