Chylolymphatic mesenteric cyst in a young adult: a case report.

Mesenteric cysts are rare, benign tumors more commonly found in children than adults, accounting for 1 in 250 000 hospital admissions. Chylolymphatic mesenteric cysts arise from ectopic lymphatic proliferation in the mesentery and usually present with non-specific symptoms such as abdominal pain, swelling, or intestinal obstruction. Their variable presentation often delays diagnosis, which is frequently confirmed during surgical exploration. We report the case of a 25-year-old female presenting with abdominal swelling, pain, and nausea. Examination revealed a soft, non-tender right hemi-abdominal mass. Contrast-enhanced computed tomography showed a well-defined cystic lesion adjacent to small bowel loops. Following pre-operative evaluation, an exploratory laparotomy with complete excision was performed. The cyst contained milky fluid, consistent with a chylolymphatic mesenteric cyst, and histopathology confirmed a benign lesion. The postoperative course was uneventful. This case highlights the diagnostic challenge of such cysts in adults and supports surgical excision as a safe and effective treatment option.