A Prospective Natural History Study of Lymphatic Anomalies

Study Description: A natural history study for lymphatic anomalies to systematically evaluate the disease phenotypes and long-term outcomes to provide improved prognostication to families, establish screening/monitoring guidelines, determine best practices for genetic diagnosis, explore family opinions, and explore fertility for those on long term medication management. This study will allow us to identify novel end points for future clinical trials. Objectives: Primary objectives: * To establish a longitudinal cohort of participants with lymphatic anomalies * To longitudinally determine the age at presentation and incidence of clinical features Secondary objectives: * To establish a longitudinal biospecimen repository * To determine the best practices for genetic diagnosis based on phenotype. * To determine the malignant potential of anomalies longitudinally Endpoints: Primary endpoints: * The number of participants with lymphatic anomalies * For each clinical feature or symptoms, the range of ages at the development of that feature/symptom and fraction of participants with that feature * Quantification and identification of novel features associated with disease. Secondary endpoints: * The number of specimens collected * Diagnostic yields by phenotype and genetic test methodology * Number of malignancies related to the primary lesion that have developed