Intra-abdominal Lymphatic Malformations: A Case Series

Background: Intra-abdominal lymphatic malformations are rare entities without a clear consensus on management or prognosis. These malformations are medically and surgically complex and often require a sophisticated, multi-disciplinary approach to treatment. Methods: A single quaternary institutional, retrospective chart review between January 2000-December 2019 was performed on all patients with an initial diagnosis of a non-solid organ intra-abdominal lymphatic malformation. Demographics, presentation, treatment, and outcome were reviewed. Results: 24 patients were identified, 62.5% were male. Median age at time of diagnosis was 2.5 years old, 33% were present at birth, 50% presented before 2 years old, and 29% presented ≥10 years of age. 75% were lymphatic (majority macrocystic), 20.8% were mixed lymphatic-venous malformations (LVM). 54% had other associated lymphatic or vascular malformations including 4 patients with PIK3CA-Related Overgrowth Spectrum (PROS), 3 with Generalized Lymphatic Anomaly, and 2 with Capillary Venous Lymphatic malformation (CVLM). Patients most often presented with abdominal pain (50%). 95.8% required an intervention. 87.5% were managed initially with sclerotherapy. Most interventions were performed for abdominal symptoms either before three years of age or during adolescence. 41.7% underwent laparoscopic or open surgery. 8.3% underwent surgery as their primary therapy. Conclusion: Intra-abdominal lymphatic malformations have a bimodal distribution pattern of presentation; shortly after birth and again at puberty. Most patients present with abdominal symptoms and have other associated vascular anomalies. MRI appears to be the most accurate modality for treatment planning. Interventional procedures such as sclerotherapy and medical therapy with sirolimus are safe and effective and should be considered first line therapies. Surgical resection is often required when the diagnosis is in question or when more conservative therapies are no longer efficacious.