Giant mesenteric cyst with ascites in a 3-year-old boy: A case report

Mesenteric cysts are rare, benign intra-abdominal lesions that predominantly affect children. They have an estimated incidence of 1 case per 20,000 children and 1 case per 105,000 adults. They are often discovered incidentally during imaging studies done for unrelated reasons. A 3-year-old child presented to the hospital with a year-long history of abdominal distension and recent weight loss. He had no relevant medical history. Clinical examination showed a distended abdomen dull on percussion, but he was otherwise in good general condition. The initial working diagnosis was ascites from portal hypertension. An abdominal ultrasound (US) showed free fluid in the peritoneal cavity, and the fluid was sampled. The serum-ascites albumin gradient (SAAG) was 1.3, suggestive of portal hypertension. He had an echocardiogram that showed mild left ventricular dilation, and he was therefore started on captopril, spironolactone and furosemide. He underwent an upper gastrointestinal endoscopy which revealed a sliding hiatal hernia and mild duodenitis, but no signs of portal hypertension. He subsequently underwent an abdominal CT scan that showed a large, multi-loculated mesenteric cyst displacing the bowel intestinal loops posteriorly. The patient underwent a laparotomy with complete resection of the mesenteric cyst. The postoperative echocardiogram showed good systolic function and all medications were stopped. After two years of follow-up, he has no recurrence of the mesenteric cyst. Despite being rare, giant mesenteric cysts should be included in differential diagnoses of patients with unexplained abdominal distension.