A rare pediatric case: Mesenteric cystic hygroma in a 5-year-old child.

Introduction and significance: Lymphangiomas are benign vascular malformations commonly found in the head and neck region, although they can occur elsewhere. Clinical manifestations vary based on location and size. Surgical resection remains the primary treatment modality.

Case presentation: A male child presented with progressive abdominal distension without associated symptoms. Emergency department evaluation revealed a palpable abdominal mass. Abdominal ultrasound and computed tomography (CT) scans confirmed a large abdominal cyst. The cyst was surgically removed, and pathological examination diagnosed mesenteric lymphangioma.

Clinical discussion: Despite their infrequent occurrence, mesenteric cysts should be included in the differential diagnosis of pediatric abdominal masses.

Conclusion: Complete surgical resection is essential for the definitive management of mesenteric lymphangioma. Partial resection or aspiration should be avoided due to the risk of complications and potential recurrence.