Summary
We report our experience of managing an 18-month-old boy in whom a giant omental cyst of 4.6 kg, which constituted 42% of his pre-operative weight, masqueraded as massive ascites. Pre-operative diagnosis and early surgical intervention were facilitated by inter-disciplinary collaboration, ultrasonography and radiological contrast studies. The differential diagnoses and treatment options of omental and mesenteric cysts are discussed. The importance of ultrasonography as an initial imaging tool for arriving at the correct diagnosis in a child with ascites of obscure aetiology is emphasized.