The LGDA is dedicated to improving the quality of life of patients with complex lymphatic anomalies by providing patient support and education; promoting and supporting basic science and patient-centered clinical research that will improve understanding of CLAs and establish best practices for their diagnosis and management; and advocating for public policies that benefit those living with these rare lymphatic diseases. Complex lymphatic anomalies (CLA) is an umbrella term which currently includes 4 overlapping, lymphatic-system maldevelopments resulting from somatic mutations in PIK3/mTor and RAS/MAPK signaling pathways: generalized lymphatic anomaly (GLA), kaposiform lymphangiomatosis (KLA), central conducting lymphatic anomaly (CCLA), and Gorham-Stout disease (GSD). Outdated terms for these diseases include lymphangiomatosis and lymphangiectasia.