Mesenteric Hemolymphangioma: A Case Report and Literature Review.

BACKGROUND Mesenteric hemolymphangioma is an exceedingly rare benign vascular malformation, with lesions at the mesenteric root being particularly uncommon. Preoperative diagnosis is challenging due to nonspecific clinical and radiological features. This study presents the first pediatric case of hemolymphangioma located at the mesenteric root and reviews the literature to elucidate its clinical characteristics and management. CASE REPORT A 15-year-old boy presented with a 2-year history of recurrent abdominal pain. The patient had no history of abdominal trauma or prior surgery. Preoperative computed tomography (CT) revealed a large, spindle-shaped, hypodense retroperitoneal mass (10.3×3.5×9.3 cm) near the duodenum and pancreatic head, with localized vascular enhancement. Intraoperatively, the tumor was located at the mesenteric root, adherent to the duodenum and pancreas, and caused localized small intestinal lymphatic dilation with chylous leakage. Complete surgical resection was achieved. Histopathological examination confirmed the diagnosis of hemolymphangioma, with immunohistochemical staining positive for D2-40, CD31, and CD34. The postoperative course was uneventful, and a follow-up CT scan at 2 weeks showed no evidence of recurrence. CONCLUSIONS This is the first reported case of pediatric hemolymphangioma at the mesenteric root. Complete surgical excision remains the cornerstone of treatment to prevent recurrence, especially given the high recurrence rates associated with partial resection. Diagnosis relies on histopathology and immunohistochemistry, as clinical and imaging findings are often nonspecific. This report highlights the importance of considering this rare entity in the differential diagnosis of mesenteric masses in children and adolescents.