Imaging of Lymphatic Anomalies

Lymphatic anomalies (LA) are a spectrum of rare diseases classified into lymphatic tumors and malformations. Complicated LA cases in the past have been called lymphangiomatosis because of varied disseminated involvement including soft tissue and viscera such as the spleen, liver and bone. Pleural effusions and pericardial effusions are often associated with these lesions. These are now classified into different phenotypes such as Generalized Lymphatic Anomaly (GLA), Gorham's Stout Disease (GSD) and Kaposiform Lymphangiomatosis (KLA). These complicated phenotypes can cause massive osteolysis causing a morbidity and mortality from infection or paralysis or worsening pulmonary function and effusions (GSD, GLA, KLA). The major cause of mortality and morbidity in these patients is the deterioration of pulmonary function by chronic chylous effusions and progressive interstitial lung disease. Unfortunately, little is known about biomarkers, risk stratification or the pathophysiology of this progression. The understanding of changes in patients' lymphatic anatomy with LA is hindered by the difficulty of imaging the lymphatic system. Dynamic Contrast Enhanced MR Lymphangiogram (DCMRL) is a technique that has recently been developed, allowing dynamic MR imaging of the lymphatic system by injecting gadolinium contrast agent in the groin lymph nodes. This technique has been previously used to identify pathological lymphatic perfusion of the lung parenchyma in patients with plastic bronchitis and neonatal chylothorax. Based on these imaging findings, a treatment algorithm has been designed and used to successfully treat the majority of those patients with these conditions.