Thoracic duct obstruction leading to chylous mesenteric cyst in an female obese adolescent: a case report.

Introduction and importance: Mesenteric cysts are rare intra-abdominal lesions, with a prevalence of approximately 1 in 100 000 to 1 in 250 000 adults. Clinical presentation can range from asymptomatic to severe. Chylous mesenteric cysts caused by thoracic duct obstruction are particularly rare and have not been previously reported in obese adolescents. Case presentation: We report the case of a 19-year-old female patient with a rare asymptomatic chylous mesenteric cyst caused by thoracic duct obstruction, which was incidentally discovered during pre-operative evaluation for bariatric surgery. The patient underwent thoracic duct decompression and a personalized low-fat nutrition plan was implemented to mitigate postoperative chyle reflux and address concurrent obesity. Clinical discussion: Mesenteric cysts can have variable clinical presentations and their evaluation relies on a range of imaging modalities. Our case highlights the importance of lymphatic system evaluation in the diagnosis and management of mesenteric cysts, particularly chylous cysts. Surgery targeting lymphatic system abnormalities offers a targeted and less invasive treatment strategy than the traditional surgical resection. Conclusion: This case report emphasizes the importance of imaging evaluation of the lymphatic system for the diagnosis and management of mesenteric cysts. A treatment strategy that combines surgery targeting lymphatic system abnormalities with a personalized nutritional plan can provide a novel and less invasive alternative to traditional surgical resection of chylous mesenteric cysts, addressing the underlying etiology while minimizing surgical trauma and potential complications.