A Giant Mesenteric Cystic Lymphangioma Causing Abdominal Mass Effect: A Case Report of a 57‐Year‐Old Woman

Mesenteric cystic lymphangioma (MCL) is a rare benign abdominal tumor. This report describes a giant MCL in a 57‐year‐old woman presenting with progressive abdominal distension and dyspnea. Examination revealed a massive abdominal mass. Magnetic resonance imaging (MRI) showed a giant cyst (34.8 cm × 46.5 cm × 25.0 cm) with T2 hyperintensity and T1 hypointensity. Laparotomy revealed a 46 cm cyst arising from the ileal mesentery. Complete en bloc excision was performed. Histopathology confirmed MCL with endothelial‐lined channels and lymphoid aggregates; the cyst contained greenish fluid. The patient recovered well with symptom resolution. MCL should be considered in the differential diagnosis of massive abdominal cysts, even in adults. Complete surgical excision remains the definitive treatment, offering excellent outcomes when performed adequately. This case highlights how delayed diagnosis due to healthcare access limitations can lead to extreme presentations requiring complex management.