Pediatric cystic lymphangioma of the retroperitoneum: A case report and review of the literature.

Rationale: Cystic lymphangioma (CL) is a rare benign tumor resulting from a failure of the lymphatic system development. It may occur at any age but it is more frequent during childhood. Its clinical presentation and location are various but abdominal CL are uncommon. Among those, mesenteric presentation is the most frequent form whereas CL of the retroperitoneum are particularly rare.

Patient Concerns: Herein, we report the case of a 17-years-old patient with no medical history who presented with right-upper quadrant (RUQ) pain, but no other symptom. Physical examination showed tenderness of the RUQ without distension. Lab tests were unremarkable.

Diagnosis: Abdominal computed tomography (CT) highlighted a retroperitoneal cystic mass potentially infiltrating the mesenterium, raising suspicion of a CL of the retroperitoneum. Diagnosis of CL was confirmed by histological analyses.

Intervention: Patient underwent an exploratory laparoscopy that infirmed infiltration of the mesenterium and allowed for resection.

Outcomes: Postoperative course was uneventful and there is no evidence of recurrence after 14 months of follow-up.

Lessons: Although CL essentially occur in children, pediatric retroperitoneal CL is a rare finding, with only 21 cases identified in the literature.In summary, CL are benign tumors rarely located in the retroperitoneum. Despite performant imaging technologies, preoperative diagnosis is challenging. Whenever possible, laparoscopic resection should be the treatment of choice. Herein, we report the largest CL pediatric case laparoscopically resected, and the first review of the literature on the topic.